Actually I'm not sure what the section "Database Summary" is all about and whte the "Unique Fingerprints" really count. Maybe they only include fingerprints in their database when they see it more than once (or the count is not live but only updated in some time periods).
As the signature changes every time CanvasBlocker is working as intended. This is the tracking information CanvasBlocker protects.

Please open an issue at https://github.com/kkapsner/CanvasBlocker/issues where we can discuss the impact of that (communication is way better there).

Please open an issue at https://github.com/kkapsner/CanvasBlocker/issues with more details
There we can communicate much better.

But as a first measure you could reset the CanvasBlocker settings.

UPDATE: it's known that the protection for the window API breaks recaptcha. If you disable and reenable it you should be prompted with a question to whitelist the specific url that is needed by it.