Unresolved New Robo 3D R1 Plus, z-axis end switch not registering

I just got a Robo 3D R1 Plus, and I'm dealing with an issue that seems to be described as one of the two z-axis end stop switches not being activated correctly. I tried steps in threads I found on this forum, but it seems my issue is different than the usual problems.

In my case, the brass hex nut that slots into the plastic housing around the threaded rod seems to be properly seated. I think the issue is that the right side of the X-axis carrier will float upwards and not push back down. If I press upwards with a small amount of force it rises off the sense switch, but it doesn't come back down. If I press down gently it slots onto the switch with an audible click.

Here's a video of the issue:

The fans may be loud in the video. I tried moving the extruder head to the leftmost stop, checking its height, and moving it to the right and adjusting the threaded rods by hand to make sure that the whole platform was relatively level. This seemed to help the software home the device, but once I tried a print it went back to the behavior of lifting up higher and higher, as if thinking the bed was already underneath.

Anyone know how I can fix this? Is there normally a bit of play in the Z axis that lets you push up and down on the housing like that? Thanks

 

I think I improved the situation by taking the arch off and loosening then tightening the screw that holds the switch housing bracket to the threaded rod on the right side. The phillips head screw you can see in this shot from the lower right side of the opened printer:

Things seem improved, but command G29 still doesn't complete correctly on the right side:

This time, however, the switch is actually remaining closed, so why is the platform rising up when it's being sent the signal that the extruder isn't touching the bed?

It's almost like it thinks that the right hand switch is electrically open. Is there a way to query the firmware to check what it thinks the state of that switch is?

 

Things have improved still further. I discovered the command to display the endstop status is M119. It was reporting the switch opened when the print head was on the right side, and I looked more closely and discovered that actually the left switch was opening up. A quarter turn of the left threaded rod fixed that, and now it seems to be able to run G28 and G29 correctly. I'm doing my first print now, and so far it's printing circle-like things, so this may be resolved! I'll leave it open just to get some input on whether I did the right thing or not.

Something I noticed is that when the extruder carrier is on the right side and lifts up, it's still the left switch that opens, not the right. I may have the x-axis assembly thingy incorrectly leveled, such that I need to turn the threaded rods some more. Anyway, good to know I didn't get a broken unit.