Comment # 6 on bug 1105461 from Wolfgang Bauer

(In reply to Alexander Osthof from comment #5)
> I've tried this package and it fixes the issue.

Good, so it is indeed the problem that I thought it is.

The revert should be fine for us (Leap 15), but IMHO the proper fix would be to
actually check the QtWebEngine version instead of the Qt version.
I'll propose this upstream, though it might probably be argued that using
different versions of Qt and QtWebEngine is not supported in the first place.
:-/

Anyway, I'll submit an update for Leap 15.0 in the next days.

Please keep using the provided package/repo for now if you want, I'll keep it
until the update is released.