Hojo8

Is there any estimate to when it'll be available from the regular update channel?

This also worked perfectly on my end. please let us know when it should be safe to switch back to the regular releases.

I did the pre-release update Marcos mentioned above (although I did have to search in the eset support on how to do that since I could not find it myself) and all looks to be normal again !!  Thanks to Marcos & everyone else!!
For others that need help with how to do it here's the help I found:
https://support.eset.com/en/kb3415-enable-pre-release-updates-in-eset-windows-home-products

Please switch to the pre-release update channel in the advanced update setup to get Browser protection module 1353 which addresses the issue or wait a bit until you get it from the regular update channel.

Firefox is my default browser (system wide).   @jackster81and @itman both confirmed this issue.   Sounds like something changed with Firefox 127.0.1 and ESET needs to be updated to support that change.  Is this something the developers/support can be contacted about?

Confirmed.
Worse, what is displayed is some type of Edge setup window which I have never seen before. I had to use Process Explorer to kill Edge running under egui.exe to get rid of the screen;

I have the same problem after installing Firefox 127.0.1 and Firefox IS my default browser.  I went back to 127.0.0 and the safe browser returned to Firefox when opened.  EDGE no longer opens.