Upgrade to 4.0/stable via snap - aft update not working

hello,
as a lot of us i ran a fairly old version of RC (3.18.7) because it ran…
now there was a push to upgrade to keep messages to mobile users…
here my problem, i upgrade to 4.0/stable via snap but nownothing is working
open the ip of the server with port 3000 gives me an
“Client sent an HTTP request to an HTTPS server.”
I have no idea what to do now…

additional info:
i run ssl via a citrix netscaler, so no need to do this on the ubuntu-server…

can someone please give me apointer or two in the right direction?

thank you all very much for taking time to read this!

i now upgraded to v6 and have the same Problem. I got it working on v5 yesterday. I found out it has to do with caddy but i can not recreate the setup I had yesterday.
As I said before, SSL is handled by a citrix gateway, so i do not need any ssl on th RC-Server.
can someone hlp? Who has the same issue?
Thanks!

for anyone stumbling over this:
the server process did not start, found this out after cheking the logs:
journalctl -fu snap.rocketchat-server.rocketchat-server

the i saw that the db was faulty and found this: Rocket.chat not starting after SNAP version refresh 5.4.5 -> 6.0.0 - #14 by arin

i then did this: Rocket.chat not starting after SNAP version refresh 5.4.5 -> 6.0.0 - #17 by stefan.l

thanks and byebye