The way I work is to use tagged text files and replace the tags with Paragraph and Character Styles.
In this beta I cannot do so. I can finde the tags and I can go to the locations but I cannot use Replace or Replace All. Using Regular Expressions or not will result in a crash. Earlier betas showed this would happen occasionally, the publisher document is under 200 pages and this works fine in the retail version.
I can send the files, text and Publisher and all the various crash reports.
Here is the latest Crash Report. I have several... [resigned sigh emoticon] Affinity Publisher Beta_2021-07-21-121209_Mac-Pro.crash