After the last update (from Windows) I have seen a bug that I remember appearing (I guess…) many years ago with Libre office.
If I underline text in writer, the underline is not always exact. preview is even worse.
However, if I print the document, it prints (apparently) correctly.
I tested it with just a few words underlined and with all text underlined.
I attach the document and the screenshots of how I view it on the screen in writer and in preview.
@guarom: Your screenshots indicate that it happens with the Desktop software Collabora Office, so you chose the wrong forum. (Collabora Online is Collabora’s web-based online office solution.)
You may want to move your posting to the correct forum or repost in the correct forum to get better answers.
Where? 
Can you redirect me?
Thanks @guarom,
And in:
Can you press the “Copy” button + Paste it here?
That will be better than having the version+build# hidden in your screenshot.
Much easier to debug or search if all the version info is pasted as text. 
I think this is an issue from LibreOffice core. I don’t know the exact cause, but it seems like this bug got introduced very recently.
2 weeks ago, someone had very similar problems on the LibreOffice subreddit after upgrading to a recent LO 7.5 version:
His screenshots look almost exactly like yours! Where:
In my testing of your ODT, it looks like this:
If I’m zooming in-and-out, you can see the underline acting very oddly, stretching/shrinking beyond the words too.
This is my LO information:
Version: 7.5.5.2 (X86_64) / LibreOffice Community
Build ID: ca8fe7424262805f223b9a2334bc7181abbcbf5e
CPU threads: 8; OS: Windows 10.0 Build 19045; UI render: Skia/Vulkan; VCL: win
Locale: en-US (en_US); UI: en-US
Calc: CL threaded
Edit: It looks like it might be this exact bug!
Looks like it happened between LO 7.5.4 + 7.5.5, so it happened within the last month!
Exact cause isn’t found yet, but I would follow that LibreOffice bug report and wait for the fix.
Once the fix gets into LibreOffice, it should get pushed to Collabora Office soon after as well.
Edit #2: I submitted your document + some screenshots to the LibreOffice Bugzilla.
Thanks so much for the document + report, @guarom !
It’s okay here.
There is no specific “Collabora Office” (Desktop) subforum, so this User Support section works.
In the future, if there are many Collabora Office questions, then those can be split into their own separate section if needed.
Of course!!! I forgot! Excuse me…
here it is:
Version: 23.05.2.3 (X86_64)
Build ID: 36c0cf311589a2d30705e299a7ce73882c6fb6de
CPU threads: 8; OS: Windows 10.0 Build 22000; UI render: Skia/Raster; VCL: win
Locale: it-IT (it_IT); UI: it-IT
Calc: threaded
I think the bug you found is roughly the same! Great!
And, just a few hours ago, the exact change was found!
The regression was accidentally introduced while an LO developer was fixing an Arabic underline issue.
They are currently discussing what the best solution might be.
Now that they know the exact thing that caused it, no doubt it’ll be fixed very soon.
I vaguely remembered having encountered the same problem many versions ago of Lo… that’s why I took the liberty of writing about a regression…
or maybe i’m wrong… 
and you are really good at identifying problems and solutions!
it’s encouraging to see how all of you are working to fix the bugs! great! 
This is now fixed by reverting the regression in the stable branches, including distro/collabora/co-23.05, which is used for Collabora Office / Collabora Online.
Great!
Will be soon an upgrade with the fix?
We expect a new release sometime this week
HI! I updated CO but the end-of-line underline problem still occurs minimally.
The line is more precise at the end of the line but does not collide correctly.
If I change the zoom the effect also changes.
The line is not totally offset, but tends to remain halfway/through three-quarters of the last letter of the line.
If I can, I’ll try to attach a new document.
The problem is currently on a working document and I need to find the time to create a suitable one… 
Version: 23.05.4.2 (X86_64)
Build ID: 979bacbb37b1ea1b42f739ea0d4a0ed22a3088f4
CPU threads: 4; OS: Windows 10.0 Build 19045; UI render: Skia/Raster; VCL: win
Locale: it-IT (it_IT); UI: it-IT
Calc: CL threaded
Any examples…
If I look at the preview you can also see it and it changes depending on the zoom
Example2.odt (524.1 KB)
Example.odt (19.5 KB)
Example3.odt (19.6 KB)
I now notice that if you underline the text and highlight/select it, it is more evident that the underline line does not reach the end of the last letter.
It was an experiment…
Example3 selection.odt (535.4 KB)
