Objects are marked as one assembly even though no weld connects them.

[K_Kubat]

I have three beam in a model that repeatedly connect as one assembly.
The error occurs in the original file after extensive work on the model or plan output.
I've encountered this three times now in my entire model.
It seems to be caused by the base plate connection. If I delete two base plate connections and add them again in a connection group, the problem is resolved for the time being.

For testing purposes, I exported only the beam and plate with their welds to a new file.
This means that there are no longer any connection/user connections.
Each individual weld is checked with "Parts connected in the workshop." Only the corresponding objects (sheet metal to beam) are displayed.
However, if I select a beam or sheet metal, they are all displayed as a connected assembly.
Each beam has 6 welds; the exported file only includes the 18 welds that connect the plates to the beams.
Nothing is disabled or hidden.
The test finds no errors.

What else could the objects be connecting that I'm missing, or is it a bug in the program?

Attached are two files, one with a user connection and one without all connection object.
The files were created with AS2025. 

[j.hamelin]

You placed a weld that holds everything together (the one highlighted).

[K_Kubat]

When I check the welds, only two objects are connected. Which connection exactly is the one you specified?
For me, everything is displayed as a single connection only when I select the plates/beams.

The weld on the stiffener, which is supposedly connected to the other beams, is in a user-defined connection with the base plate.
After re-creating it, everything is correct at first, but after working on the model for a while (in other areas), the beams become an assembly.
This merging with a weld from a connecting joint between the beams and the plates is done by Advance Steel itself.
I haven't created a connection.

How can this happen?

[j.hamelin]

Honestly, I don’t know why, but removing the welds on the center and end column baseplate stiffeners solved the issue. It probably depends on how your user-defined connection was created.