I used some Java services in docker on thier free tier and found them to be big memory hogs. Have a look at the logs for OOM errors (Out of Memory?).
If you are using thier free tier thier arm offering has more memory (assuming what you are running would run under arm).
Nothing original;
lappy386 - my laptop
desktop (very original)
mainframe - NAS/nextcloud/email
orac - multimedia/jellyfin/photoprism/owntone
bemo (I know, I cant spell) - pihole/unbound/homeassistant/wireguard
Future servers will be named after any TV scifi tech that takes my fancy. (twiki, zen (or was it xen?), data, k-9, ada, marvin, romi, holly, bender, dolores). Any suggestions?
It does allow sync for each of your LDAP users, but it may require an app on your phone. I use the same setup and have had success with DAVx on android.
Or the Nextcloud plug in Memories.
Doesn't SoGo use Activesync? This wouldn't need an app on your phone.
I tried the same setup as you a few years ago. It worked, but I didn't like SoGo for email so moved to Nextcloud/SnappyMail and DAVx/K9 on my phone. Have been using this fine since.
I use RSS Hub https://docs.rsshub.app/en/
Agree about the Nextcloud client, but it's easy enough to replace it with the SnappyMail plug in which works a treat.
According to the release you just update the version in the docker-compose.yml file.
I found the following site to be useful, but agree it's a bit overwhelming. https://browse.feddit.de/