You must have done something wrong, of course the applied domains are also transferred. Maybe you didn't use the export function but just copied the source?
One of those (either annoyances, headers, or popups) broke a fork of Stylish. I'd click on the icon in the toolbar and the drop-down wouldn't appear. I noticed the user style also broke AWS navigation.
None of those sheets except for Annoyances should be applied globally.
I don't guarantee Annoyances won't break other things, but I do guarantee that the others will.
Assign the to a nonexistent URL or domain initially, or disable them.
If you've got specific bugs with the Annoyances sheet ... I may be able to address them.
My usual first-stop debugging tools are adding either an outline or background colour to an element:
outline: solid 2px red;
background: #faa;
... which tends to show what rule(s) are being triggered. If something breaks, add those rules, and disable the "display: none;" one.
I'm also finding that the shift to "display: flex;" styles is breaking some of my assumptions. It's no longer safe to presume that everything is displayed as one of block, inline-block, or inline.
Position directives are also problematic: initial, static, relative, absolute.
That said: I've evolved those styles over a few years, and they tend to work reasonably well. Some nursemaiding required.
I've got a system where I use a set of standard styles applied broadly against many sites.
E.g.,
Annoyances -- applied globally to all websites by default: https://pastebin.com/raw/GrE9KX6D
Local Gifs: https://pastebin.com/raw/tn7cqGtJ (Exceptions to global gif filtering)
The following break on many sites too much to be applied as default, but can be used fairly generally to selected sites as needed.
Animations blocking: https://pastebin.com/raw/7Gjxj6AT
Headers / Footers: https://pastebin.com/raw/PsXWhUGf
Popups / Overlays blocker: https://pastebin.com/raw/VcgNNwDp
"Unstyled" CSS: what I apply to unstyled / minimally styled pages: https://pastebin.com/raw/rtfev3vj
For development / testing / debug:
Debug CSS: https://pastebin.com/raw/Z3kFrRQy
(Highlights class/id and entities in page.)