Upgrading to 4.38.121 does not fix.
As Slack is not supporting officialy Arch, they will not fix it. But I got this bug report from their support: https://github.com/electron/electron/issues/41839 which hs many similar issues linked / mentioned in comments.
Pinned Comments
ogarcia commented on 2020-02-06 11:44 (UTC) (edited on 2020-02-06 11:44 (UTC) by ogarcia)
Please, don't ask for add
lsb-release
as dependency. In Arch Linux this package is not needed to run Slack Desktop.And before asking for any other dependency as
make
orpatch
or whatever, please read the wiki.