I made my own iMessage stickers, which I installed to my and my brother's iPhone, without a dev account.
After maybe 2 weeks, stickers stopped work on my iPhone as well as iPhone of my brother. I have to delete it, and install it again.
Is there any time limit of the provisioning profile, how long it works without dev account?
The free provisioning expires in 7 days (previously it was 90 days), you can see the expiration date in Xcode selecting the
iicon near the provisioning profile like in this image: