when changing identity in new/reply/forward, reply-to does not change accordingly anymore [SOLVED: caused by SmartTemplate add-on]

Until about 24 hours ago, I happily used my various identities (6 of them, 5 under one POP3 account, and one a separate IMAP account). I use TB 68.3.1 on Win10 Home (1909, build 18363.535) Until yesterday, whenever I'd write a new message, a reply, or a forward, but decided at any point to change the identity (mostly to change the signature and/or the reply-to address, I have multiple aliases set up inside my one POP3 account depending on the type of contact I have, eg. one for sport, one for work, one for friends) if I wanted to change the identity, the following things would change accordingly: * identity name * reply-to address * signature All of a sudden, only the identity name would change, but signature and reply-to would stay the same. I suspected an add-on to be in the way (SmartTemplate's "you now need a license" message made me suspect that); I played around with my add-ons a bit, seeing if disabling or updating (all set to auto-update) would do the trick, but nothing changed. Since then, I have deleted my identities, and re-created them. That seemed to help a bit. Now, the identity name AND signature change accordingly again, but no matter what I try, I can not get the reply-to address (fyi: I explicitly set them up in each identity) to change along with the identity name and signature. Is this a bug?