Suspended tabs do always show half sized sceen caps on the left side of the window leaving the right side blank (white).
This happens for some month now no matter what combination of settings is applied in dark and in light mode and without any other chrome extensions installed.

my guess would be that this is related to automatic hi-dpi scaling.
Since you apparently have no idea, @philoupd .. and our dear friend @ossilator couldn't be bothered to tell you, I would like to warn you that anything past version 7.16 of this extension is widely agreed upon to be malicious. Please see the discussions here:
https://github.com/greatsuspender/thegreatsuspender/issues/1263
and here:
https://github.com/greatsuspender/thegreatsuspender/issues/1175
Version 7.16 can be found here:
https://github.com/greatsuspender/thegreatsuspender/releases/tag/v7.1.6
Instructions for installing it directly from the source code are in the README for the extension, located here:
https://github.com/greatsuspender/thegreatsuspender#install-as-an-extension-from-source
If you choose to install 7.16, make sure that you unsuspend all suspended tabs before disabling / removing the current version.
Thanks for the hint. Installing 7.1.6 makes me feel much better now and also fixes my issue.
Most helpful comment
Since you apparently have no idea, @philoupd .. and our dear friend @ossilator couldn't be bothered to tell you, I would like to warn you that anything past version 7.16 of this extension is widely agreed upon to be malicious. Please see the discussions here:
https://github.com/greatsuspender/thegreatsuspender/issues/1263
and here:
https://github.com/greatsuspender/thegreatsuspender/issues/1175
Version 7.16 can be found here:
https://github.com/greatsuspender/thegreatsuspender/releases/tag/v7.1.6
Instructions for installing it directly from the source code are in the README for the extension, located here:
https://github.com/greatsuspender/thegreatsuspender#install-as-an-extension-from-source
If you choose to install 7.16, make sure that you unsuspend all suspended tabs before disabling / removing the current version.