Hi! Thanks for reporting the error. That unstyled error page signals a low level bug. Without disclosing anything private, is there anything particular about the notes you were navigating through (e.g. big attachments)?
Hmm the notes are nothing special in themselves; managed to replicate it with notes which were just text, with a few web and wiki links in.
My totally unfounded speculation is that it’s not the specific notes, but rather switching between them quickly causes something to fall over - I’ve clicked between the same notes at other times and it’s been fine.
I’ve also managed to replicate this in Arc as well (1.82.1), so it’s not safari specific.