Massive issues after updating to 4.8.4

Hello,
after the update to 4..8.4 we encountered massive issues on our site.
They are:
1: Background color changed specially in areas with alternate background color
2: Elements changed their color
3: mysterious texts coming out of nowhere “like “Click here to add your own text” in elements like iconboxes – even if there was other text before
4: massive loss of textcontent (replaced with “Click here to add your own text” or similar)
5: single images arent displayed anymore
6: Videos dont show up
7: Fonts changed
8: Margins & paddings changed to inacceptable high values
9: Tabs & toggles are empty
10: Doubled scrollbars
11: and more

We used the color scheme: “Dark Blue” – fullwidth

Replacing 4.8.4 with 4.8.3. or older version brings back the original content, the correct colors and fixes all issues mentioned above
Its repeatable as often as you want by “Update & downdate” between 4.8.4 and 4.8.3
This looks like massive bugs in your theme .

heiraten-mit-stil.eu
But of course we didnt leave a destroyed website online.
So you wont see anything.

Martin