Mounted network drive disconnects when turning off WiFi

I've been searching the internet and specifically this forum but to no avail. So I humbly present my question here.

At work we have several iMacs 27" 5K with Intel chips from the last generations before they shrunk into colorfull candy colored M1's. We connect to a disk array with network drives that is connected to a new mac Mini (M1) that handles the array. Connection between this Mini and the 96Tb array is a Thunderbolt 3/4 cable. The array is not connected to the network directly, the mac Mini is. It is wired with an Ethernet to a 24 port switch. From this switch ethernet 5E cables go into the workspace and split into two other switches that connect to the workstations.

Everyone has the network disk mounted automatically by adding it to their login items. So far, no problems.

Here's the kicker. When someone turns off their WiFi, the network disk disconnects. Re-selecting the disk in the network-tab in the Finder starts it right back up (looking at the path, its seems to be an SMB connection). If you keep WiFi turned off, the connection is stable and fast. Restarting the Mac with Wifi on, seems to connect the disk through wifi instead of hardwired. Disconnecting the wifi will crash the disk.

Unmounting the disk, turning wiFi back on, re-selecting the drive in the network tab in Finder, mounts the disk back on the desktop (still with SMB in the path). Turning WiFi off, disconnects the mounted drive again.

So, workaround: keep WiFi off at all times to force a hardwired connection. But we control several things with WiFi (Sonos speakers, printer, etc.) so would like to keep using WiFi.

Any takers?