I also have the same problem (not matching the text).
I first thought that it was due to a couple of line breaks in the pop-up message (you know, a br in a <> I can’t add it here properly because this editor adds a new line!)
I have that BR problem in a few places (I’m porting tests from Selenium IDE) but I have got round it by removing the BR and adding a wild card (*) instead. The wild card trick doesnt work here. You can replace all the text with a wildcard, and it still wont match, so now I’m wondering whether wild cards work on this particular assertation.
What would be great is if Katalon rather than just saying that the text doesn’t match what was expected and printing what was expected to log, if it also added what text it got to the log too (line Selenium IDE does). That would help a lot in trouble shooting.
Anyway, it would be great if someone has found a workaround for this…?