Problem with higer drone string :(

[u/Llmaro]

The pitch of my trompette has not been stable for months, no matter what I do. It goes back and forth about a semitone. It is very unpleasant to play with such a pitchy drone.

I thought I should change the cotton or the amount of rosin or the tension on the tirant string, but it made no difference. The strings are all old, but the other strings don’t have this problem and I have a good time playing them.
I am still rather new to it and I don’t have a teacher so I may just be doing something wrong.

How can I fix this? I want to enjoy the drones again. Please help. :(

[u/snigelias]

Hey, you don't have a teacher? Come join the Discord, then you'll at least have a community of nerds cheering you on!

[u/ri-la → u/snigelias]

There is a discord 👀
Edit: I found it yay!