Goto the URL opera://about, take note of the "profile" path, close Opera and create a blank file named "Preferences" (not "Preferences.txt") in the profile folder. Then, it should only show on updates.
There's a fix coming so you don't have to do that (or delete opera_gx_splash.exe after every update).
Sounds like a DNS issue on your system. Until you figure it out, in Opera, goto the URL opera://settings/system and enable DNS over HTTPs and restart Opera.
@venividivici It seems that once you synced up with Opera, you must not access Youtube back on Chrome or this issue will happen. Same thing happened to me.