I found that after I had finished a knowledge transfer I went to progress another character through the same mechanic I was unable to. I was unable to progress another character, with my main for instance, however i didnt select my main as the one to transfer knowledge and now I cannot progress another character in my roster to where my main is currently. This has only happened to me once as I have only done this in-game mechanic once.
The steps to this bug are as follows.
2.1 Get a character to level 50 call this (1)
2.2 powerpass another character to level 50 call this (2)
2.3 knowledge transfer and make an character then say you select (1) you could be transfered with (2)
This happens in the stronghold.
Thank you for your time.
If anyone would like to revert or help me with these changes my mains tag is Hotgrl.