ThriveTheme Architect A/B Test nor working

Here the problem I asked ThriveTheme support:

Hello
Can you please show me how I can get a A/B test for an existing page.
If I try to do so e.g. opening page home (angegkommen) and I try to use on the right hand side the A/B button (Create new A/B test),
all what is happening is, that the following message/URL is showing up in broser:
https://www.spiritquelle.de/?thrive-variations=true

This was the answer of ThriveTheme support:
I have logged in to your site and opened your home page with Thrive Architect. I was able to replicate the issue you’re experiencing where I get a blank page whenever I tried to create an A/B test.

I then went ahead and did plugin deactivation to isolate the issue. Upon further testing, it seems that the Asset CleanUp: Page Speed Booster plugin is the culprit.

After deactivating that plugin, I was able to open an A/B test without issue as seen in this screen recording I made – https://share.getcloudapp.com/v1uezeBJ

Our products are written according to the WordPress Codex Standards. Given that, could you please reach out to the developers of the Asset CleanUp: Page Speed Booster plugin and have them check the issue you’re experiencing? You can also ask them if there are settings that you can enable/disable to resolve the issue.
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Can you please tell me what settings has to be changed to solve this problem?
Thank you a lot
Michael

The page I need help with: [log in to see the link]