Issue with form

Hi, 

I'm experiencing an issue with form submissions - see error message below. My website uses Weglot for multi-language and the issue appeared after we set-up subdirectories. 

Squarespace support ruled out Weglot as the problem source and indicated that: 
"Because the issue was resolved by disabling scripts, the problem is likely caused by custom code you’ve added to your site. Troubleshooting code falls outside our scope of support, so we can’t pinpoint the exact code responsible for the issue. I’d recommend reviewing any custom scripts you’ve added to code blocks or code injection and try removing them one at a time to determine which one is causing an issue."

Has someone had a similar experience? Or any idea how to fix?

Thanks!

Tried a valid address and the issue persists: Link here: https://felfel.ch/probieren

I am also experiencing this issue - is there any fix? I excluded the URL where the form is but it still persists.

Same here! Is there any workaround or solution to fix this?