Do you use Safari Technology Preview? Or was this on regular Safari?
To help understand more, I'll need a sample app that can reproduce the issue and a sysdiagnose.
Are you testing with unsigned extensions?
Thank you for reaching out.
I found the issue, and it had nothing to with Safari. The problem was me, misusing Combine: I wrapped calls to SFSafariExtensionManager.getStateOfSafariExtension and SFContentBlockerManager.getStateOfContentBlocker in Future<> and didn't keep AnyCancellable which was produced as the result. Thus, the result of the operation never made it to the state.
Curiously, I remember the same code working before. Maybe during Beta times, there might have been a bug when a Combine chain wasn't disposed immediately. So I started looking into it thinking nothing is wrong with my code Everything is fixed now.