We have used this plugin for years, but lately it’s behaving a bit erratic.
The issue is that, while it’s possible to set a birthday on the my/preferences/profile and it claims to save it, effectively the birthday date is not persisted and it’s gone once the page is reloaded.
However, in another Discourse instance (same version), this behavior seems to happen only to some accounts and not others. I can’t figure out the pattern, but it’s affecting other users, so it’s definitely not just me. 
We only noticed once we jumped from 3.5.4 to the current ESR (2026.1.3) where it now comes in the core. Anyone else experiencing this where saving the birthday appears to work… except it doesn’t persist?