Hi Nastia!
I encountered this issue most recently this morning. I went ahead and exported my customer’s form to one of my test websites (for their privacy) and it looks like the issue doesn’t show on my Astra themed test site BUT it’s showing on my highend test site – highend is the theme my customer was using too. Maybe it’s an issue between forminator and the highend theme?
Example of the form: https://bskyhighend.fourpawscakes.com/test-form/