Networking Problems between a QNAP-NAS and my 2012 Mac Mini running Catalina

In my home network, I have a QNAP-NAS connected via Cat 5 to my network. It has a static IP. I can Ping the IP without problem. I can't connect to the NAS with my Mac Mini. I can connect to the NAS with my 20212 MBP 13" running Catalina. I have removed and reloaded the Qfinder webapp used to make the connection and provide access to the admin page on the NAS. I have completely reloaded the Catalina from the internet.

Now the most important piece of information on my problem: I experienced an event that started with a loud bang and I lost power or at least the Mini restarted. Having said that the Mini in on a 1500ma UPS.

Before starting down some new path, my computer works like advertised in every way I have come across in using it for about 3 week or more. More info: I have a ups on my Inetrnet cable modem, and a separate ups on each of the 2 Access Points of my mesh network. The computer has been shut off and restarted. It has been set down overnight and longer. The NAS the same thing.

I have tried three different browsers on my Mini. I can stream video with my internet connection. Unfortunately the CLI "networkQuality" is not available for Catalina. I have tried to connect to the NAS in at least 3 different ways.

1. Qfinder., 2. direct entry of the IP in the address bar, 3. using the macOS "GO" menu to select "Connect to Server" which is the way my network was configured before the problem showed up. When I booted my Mini it would mount 2 of the partitions on the Mini. It has worked for several years without problem.

First question: any thoughts on fixing the problem?

Second question: Are there any network logs of failed connection captured on the Mini?

Third: Are there any hardware or software variables that have not been tested and passed?

HELP