Aegisub - Get rid of Spaces/Overlaps in Opaque Box

[Headwipe]

Hello,

I have karaoke subtitles and they also have their own font, etc. I put them in an opaque box and made them transparent. Now I have the problem that there are small gaps between the words. How can I get rid of this without losing the formatting and style. In the end, I want these subtitles to be hard-coded, but that's not a problem.
Does anyone have any idea how to do that? Or is there another software with which you can do that?

I have already tried to change the values for the border and the shadow, but I got no result.

[Attachment 60526 - Click to enlarge]

[Attachment 60527 - Click to enlarge]

I would appreciate any help.

[Headwipe]

Does really nobody know a Solution for this?