yup, seems two overwriting each other, but there is only one site. if I click the tab it clears, but as soon as I go to another tab, it's back.

I submitted a bug, but figured I'd post here also as I can include an image..
2nd tab the text is always garbled, and only the 2nd tab, 1st-3rd, 4th and on no issue. Sites, URL what ever doesn't matter.

Mac Opera, (just downloaded like an hour ago)
Mac OSX Mojave (10.14.6)
Mac Mini (late 2014- 2.6Ghz - i5, Intel Iris 1535 graphics)