Tahoe 26.1 making Safari freak out

I installed the latest MacOS update, 26.1, and upon launching, Safari gave me the beach ball of death. I did not see the 1Password extension anymore in window header, so I suspected I may have had an old Safari extension, so in the occasional windows where I could operate Safari, I was able to remove all the extensions, and reinstall the newest 1Password extension.

As soon as it was installed, the extension briefly appeared in the title bar, then went away, then came back, and it continued to do that back and forth, chewing up CPU as it went, until it was unusable. It works fine without the 1Password extension installed.

Not sure what to do next. I've already restarted everything, updated everything, reinstalled everything. Any troubleshooting ideas?

Thanks,
/mike