Why does the D-Link DGS-1210-52MP Switch bring down the entire network in about 1 day?

Question

D-Link

Why does the DGS-1210-52MP router bring down the entire network in about 1 day? it just seems to get confused in the routes or goes into some kind of mode and the whole network lies, I reboot again for 1 day it works normally without a problem.
1 nans, works in unmanaged mode.

I am attaching a mini network diagram below:
The router itself has the address 192.168.50.55
There are also 2 Wifi static points, also somewhere in the circuit plugged into free switch ports with addresses 192.168.50.20 and the second point 192.168.50.30

What input data is still needed to get answer?)
AD+DNS+DHCP on 1 server
Separate file server
Everything is wrapped up on 1 physical server.

Do not swear at the network, I picked it up in a couple of hours. it was necessary to plant 50 people in 48 hours to make it work.
In the near future I will put normal sockets on all floors and there will be 1 PC 1 socket from the Switch.

Answer 1

It would be interesting to look at the switch logs.
And to begin with, I will suggest that you reduce the broadcast domain, divide the network into vlans. In the diagram I see Mikrotik, he will definitely cope.
And separate the management network into a separate vlan, isolate it from users.
And the rest is just logs, dumps.