Man, is that obnoxious. Yet another example of a DRM effort that will probably inspire more piracy.
I'll buy an ebook but read a copy from LibGen because that version doesn't have my email address as the first sentence of every page. It's hard to read books instead of doing something more entertaining, this minor annoyance doesn't help.
I’m sure this is software related, and I’m on the iPadOS 16 beta, so it may be less of an issue for others. On my phone it folds into the header and truncates, but on the iPad it is super obnoxious.