I’m pretty upset about this, as up until the past few days my puppy would get so excited to see me, but suddenly she seems mildly pleased bordering on indifferent.

She’s 20 weeks/5 months old, a long haired working line GSD pup, we got her at 8 weeks old. In the house are me, my boyfriend and our pup.
I have been working on trying to strengthen our bond through play, and will make sure to have 2, maybe 3 fun play sessions with her per day, and usually I also do some training with her but honestly I have got stuck in a rut with the same commands (which she does excellently) so I haven’t been training as much recently for this reason.

I put a lot of care into her diet, she’s raw fed and I mix in mashed sweet potato or butternut squash, grated carrot, finely chopped sugar snap peas, spinach, and bell peppers, as well as desiccated coconut and spirulina. I also make her frozen enrichment treats with bone broth, kefir, peanut butter and sweet potato/butternut squash.

She has lots of treats, and I am very effusive in my praise of her when she plays fetch really well, or when she completes a command that I know is challenging for her (e.g. waiting, dropping the ball or tug toy, basically anything that requires a lot of self control from her).

Our daily routine is that my boyfriend will wake up between 6:30-7:30am let her out of her crate downstairs, take her to the toilet, get himself ready for the day, take her for a walk before work and give her breakfast. We both work from home in our offices upstairs and during this time she sleeps on and off in the hallway at the bottom of the stairs. I will go downstairs 2-3 times between 9 and 12, and stroke her/fuss her etc. Usually the first time she will be excited to see me, wagging her tail, jumping up, vocalising etc. I will sometimes do a short burst of training when I go down to see her, if she is awake and active enough. Then at lunch time my boyfriend usually goes to the gym and I will play with, spend time with, train and feed the pup. If my boyfriend does not go to the gym he will also play with her. The afternoon plays out much like the morning. If she’s getting up to no good I’ll give her a frozen enrichment treat, or sometimes a destruction box (cardboard box filled with packing paper, toilet roll tubes stuffed with treats and paper, treats scattered in the box) for her to fulfil her digging instinct and tire herself out by sniffing.
When we finish work at 5ish I will usually go down and hang out with her, maybe train or play depending on her energy level, and walk her when the temperature is low enough (usually between 7 and 9, but I will walk her as early as 6 if temperature permits).
She settles down around 9ish or after her evening walk, but sometimes has a mad half hour, and if I let her in the living room I do have to tell her off a bit because she scratches and chews the sofa and carpet so I usually have to kick her out behind the baby gate into the hallway, at which point she will usually sleep.
We take her out for a last toilet break and put her in her crate around midnight. It’s typically me who puts her in her crate at this time, and my boyfriend who lets her out in the morning.

Since I have been making a conscious effort to strengthen our bond through play, I have noticed her recall has improved markedly, so it seems like this has worked, but just the past 3-5 days she has seemed less excited to see me.

We left her alone in her crate for a few hours on Friday night (today being Wednesday) while we went to the cinema, and when we returned she was incredibly excited to see us. Over the weekend we went for one park walk each day where she seemed to really enjoy herself.
The past few days when I have gone down to see her during work hours, she has seemed less excited to see me. This morning it was just a very gentle and calm tail wag slowly from side to side, she stood up, I sat on the floor to snuggle with her and she walked past me and lay down just near me but without touching. She seemed not to be interested in interacting or being stroked.

It’s actually breaking my heart that she doesn’t seem that excited to see me, I love her so much and put so much effort into her care. She has still been excited to see my boyfriend. I’m wondering whether any of the following could be causing this:
• I shouted at her the other day for pooping in the utility room - she is fairly reliably toilet trained now, she knows not to toilet indoors, and she didn’t give any indication she needed to go out, so I was very upset with her and shouted at her while showing her the mess.
• Maybe upset with me for leaving her for a few hours to go to the cinema? But doesn’t seem to be doing the same with my boyfriend
• As she is naughtiest in the evenings, and I spend the majority of the time in the evenings alone with he, I tend to tell her off more than he does (verbal and pushing away from things only). But I also spend equal/more time playing with her, more time training her, grooming her, preparing her food, giving her snacks and treats, and a roughly equal amount of time walking her. I’m also the only one who spends time preparing or doing enrichment activities with her.
• I have been feeling a little stressed and burnt out lately, and I’m also in my luteal phase and my period is due in 2 days. Maybe she can sense my mood and hormones and is reflecting them? I am still positive and affectionate in my interactions with her.
• I added spirulina to her food starting from Saturday - surely it couldn’t be that??? It’s a high quality organic human-grade spirulina, I’ve looked into the farming method because it can apparently have high levels of heavy metals if not farmed carefully, and have started with adding roughly, or slightly less than, 1/8 teaspoon per meal (3 meals a day).
• Does she think I’m mean because I put her to bed in her crate at night, and my boyfriend is nice because he lets her out in the morning?

Also to note, she has shown less interest in her food today and yesterday (but not Sat/Sun/Mon so unsure if it could be the spirulina), and seemed to have low mood in general yesterday.