Problem after reboot of my ucs

i have 2 ucs server each of them as a VM.
my ucs1 hold the user
the ucs2 holds nextcloud.
each time i do a update or need to reboot i have problem with my ucs?
after a couple of reboot it works then but how to solve it faster this problem!
Today is the Problem a ERR_CONNECTION_REFUSED but both ucs are up and running.
on my ucs1 i have no problem to login in - then to connect to nextcloud make the error

have a nice day