When I visit any 1Password Support Forum thread using Safari Technology Preview (currently I'm using v81, but I think this was happening in v80 also), I can only see the initial post -- no response from Agile Team members to that poster or other forum members chiming in on the thread. I've tried this from multiple machines, and it's happening on all of them. If I view the same support thread using Standard Safari or Firefox (I haven't tried with Chrome or other browsers), every posting within the thread is visible. Though I haven't tried to provide my own response to an already-started thread via Safari Technology Preview since seeing this problem, it seems possible to do because every thread offers the "Leave a Comment / multi-line edit box/ [Preview] [Save Draft] [Post Comment]" block at the bottom of the page. In other words, though the initial and concluding parts of a given thread are visible, it's the parts of the thread that are between those items that are missing. See my attached screen shots.
Safari Technology Preview 81:
I am aware of other problems that 1Password and/or its extension is having with the most recent versions of Safari Technology Preview, and what can and can't be done at this time to solve or get around the problems being faced when using STP -- indeed, that's why I was visiting the applicable 1Password forums this time around -- so it's rather ironic that Agile's forum software itself is having trouble rendering the very posts meant to help folks like me:
1Password Version: 7.3.BETA-12 (70300012)
Extension Version: 7.3.BETA-12 ("from 1Password 7"
OS Version: 10.14.5 Beta (18F127a)
Sync Type: Dropbox + 1Password.com account