Problems uninstalling Jetpack

Hi! I am struggling to find out why I can’t uninstall Jetpack.
Here’s what happens:
1. I deactivate, then delete the plugin
2. Next time I log in, it’s back again
3. I try deleting all the files with “jetpack” in the name via File Manager on my host’s website, for example:
the plugin folder if it’s still there
/.wp-cli/cache/plugin/jetpack-9.2.1.zip
/public_html/wp-content/themes/sinatra/inc/compatibility/class-sinatra-jetpack.php
4. If I delete the file in my theme directory (the last one), I get a critical error and the site goes down.

I’ve talked to my host support at Bluehost, to various different people over the last 7 days, but they’ve been of no help so far. After their tech support did something on my site yesterday I’m getting the following in my Site Health:

1 critical issue
Your site could not complete a loopback request
Performance
Loopback requests are used to run scheduled events, and are also used by the built-in editors for themes and plugins to verify code stability.

The loopback request to your site failed, this means features relying on them are not currently working as expected.
Error: cURL error 28: Operation timed out after 10001 milliseconds with 0 bytes received (http_request_failed)

I contacted Bluehost support again and they told me to not give attention to this error. As for the main issue, not being able to uninstall Jetpack, they told me to keep deleting the plugin and someday it will disappear completely(?).

I’m not sure how to move forward from here, any ideas?
Thanks!

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