Lightburn / Totem S / Hard limit triggered

The error is indicating that your limit switches are being triggered. Based on your description it seems they’re not actively being hit.

First need to sort out if the signal is coming from the switches themselves or something on the controller or software.

Try to recreate the error. Run a dummy job and manually trigger the limit switch. I would focus on the X-axis switch since you’re getting the issue from L to R. Do you get the same error with the same symptoms?
See if you can identify some mechanical reason why the switches would be getting triggered. Are the connections loose? Is the switch somehow defective and mechanically closing just from rapid movements? Is the switch electrically defective?
If you cannot suss out any issue with the switches themselves try disabling hard limits in controller ($21=0)
I know it might be hard to test but see if you still have the issue with hard limits disabled.
Other things to consider:

If you have spare switches try swapping out
You could swap switch location… does the issue change from X to Y axis? If so, likely switch issue. If not then error elsewhere.