Thanks for your input. But this doesn’t seem to work, resulting in the following error:
$ sudo pacman -Syu
:: Synchronizing package databases...
endeavouros 25,9 KiB 83,5 KiB/s 00:00 [------------------------------------------------------------] 100%
core 132,0 KiB 257 KiB/s 00:01 [------------------------------------------------------------] 100%
extra 8,3 MiB 4,08 MiB/s 00:02 [------------------------------------------------------------] 100%
community 45,0 B 100 B/s 00:00 [------------------------------------------------------------] 100%
multilib 143,1 KiB 292 KiB/s 00:00 [------------------------------------------------------------] 100%
kernel-lts 2,1 KiB 130 B/s 00:17 [------------------------------------------------------------] 100%
error: GPGME error: No data
error: kernel-lts: missing required signature
error: failed to synchronize all databases (invalid or corrupted database (PGP signature))
Via the Welcome-dialog, I’ve changed the mirrors already a couple of times to different countries, but this didn’t bring any solution either.
I’ve tried this post as well (and changed “pacman-key --populate archlinux32” to “pacman-key --populate endeavouros”): https://ostechnix.com/solve-error-required-key-missing-from-keyring-in-arch-linux/
But without any result solving the issue. Also the following link didn’t bring me any solution: Can't update, "error: failed to synchronize all databases"