@Pulstura
From what you described it is possible that next Deco firmware will not fix that problem.
WiFi mesh is a set of nodes broadcasting same SSID, but with different signal strength which depends on distance to the node. If your PC network card understands WiFi mesh, it should select strongest signal node and connect to it. Because it does not do that, it could mean your PC network card is thinking there is just one router with that SSID and does not look for other nodes.
Next Deco firmware will use WiFi mesh specific protocols to recommend device which node to connect to, and you can specify that node in Deco app. Because your PC network card does not understand WiFi mesh, it will not understand Deco recommendations and will ignore them.
Check recommendations I made in previous conversation on that topic: Device not connecting to the nearest/fastest Deco, see post #7 on first page of that forum topic. What I said for laptop in Item 4 also applies for PC desktop. These were recommendations for WiFi5 Deco, because your X60 supports WiFi6, if your network card allows to prefer WiFi6 connectivity, set that preference.
If nothing helps, you may need to find a replacement for your network card. If it comes to that, look for new one with WiFi6 support. It is the newest WiFi standard, network cards with it are also supposed to understand WiFi mesh.
You can Google "WiFi roaming aggressiveness" for more detailed conversations on that topic, and for helpful tips.