Can't add Subscribe block to Block Layout

Problem/Motivation

In my site's Block Layout, I tried to add the Subscribe block but it never gets to the configuration screen.

The only error logged in watchdog is:
The "views_exposed_filter_block:search-search" was not found

The site is Drupal 9.3.9 running on PHP 8.0.16.

I don't know what the subscribe block has to do with the exposed filter for search, so I can't rule out that is some kind of incompatibility or configuration issue involved. So possible that this is more of a support request, but I haven't had much luck with this module unfortunately.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes