@BAS-Viet-Nam Okay, thank you for the hint. Worked on many sites with these 2 functions without any problems. So I will try it with "Wait while element exists" on this specific site.
Hopefully I don't get in an endless waiting-loop ;)
The issue was with window.outerWidth == 0 in BAS, and some startnge code window.outerWidth || window.innerWidth from recaptcha service. If window.outerWidth == 0, so function, which calculates screen width, returned window.innerWidth which was always 304px, because code executed in captcha frame.
