License in question: https://github.com/papermark/papermark?tab=License-1-ov-file It is AGPL, basically means:

You have to share the source code even when the user interacts over the network with the software.

The project which uses that code, must also be AGPL,

There are ways to separate it and go around it, for example, using an AGPL auth server shouldn't affect the code where your business logic lives

I am sure they could have found a way to design their product to be compliant, especially following past drama.

This is assuming the code is indeed copied, since we don't know that for sure, it does look very similar but I am not sure how that is enforced