Problem with overlay, face inheritance and :before-string

[Sebagabones]

I am reporting a bug related to an issue reported on the indent-bars package (attached below is an image of the original problem). The author of this package (@jdtsmith) suggests that this is an issue with lsp-ui-mode:

this is almost always an issue of other packages applying styling at the beginning of lines, and failing to account for :stipple property there. This type of problem is why by default there is no bar at column 0.

Try disabling starting-column. Does the issue go away? If so, this is a bug in lsp-ui-peek which you'll need to bring to their attention.

ref

Disabling starting-coloumn did make the issue go away, so I am opening a bug report here.

Sadly, my elisp knowledge does not extend this far, however I am more than willing to help test solutions

The issue is that when using indent-bars with lsp-ui-mode, when using lsp-ui-peek, this happens: