librealsense: rs-multicam sometimes crashes upon startup

Required Info
Camera Model	D435
Firmware Version	05.11.01.100
Operating System & Version	Linux (Ubuntu 18.04)
Kernel Version (Linux Only)	4.15.0-50-generic
Platform	PC
SDK Version	2.22.0-0~realsense0.1106
Language	C++
Segment	Multi-camera

Issue Description

I am trying to run the example rs-multicam with three D435’s (without hardware sync). Most of the time, it crashes with the error:

RealSense error calling rs2_pipeline_start_with_config(pipe:0x563c0c05c520, config:0x563c0c05c540):
    hwmon command 0x10 failed. Error type:  (1).

Other times, it crashes with this error:

RealSense error calling rs2_pipeline_start_with_config(pipe:0x55d55bb5e0b0, config:0x55d55bb5e0d0):
    hwmon command 0x30 failed. Error type:  (1).

I’ve gotten this once:

RealSense error calling rs2_pipeline_start_with_config(pipe:0x55dbff3d8400, config:0x55dbff3d8420):
    hwmon command 0x2c failed. Error type:  (1).

There is no other output.

Sometimes, it does run successfully and show the 6 streams (depth and color from each camera). I don’t recall this happening with SDK version 2.18 (the last version I used). Anecdotally, it takes longer to reach a hwmon 0x30 crash than hwmon 0x10. The crashes become less frequent if I use two cameras, and apparently non-existent if I only use one.

The RealSense Viewer can stream depth+color from all cameras simultaneously, without error. I wrote another program to open streams individually (i.e. using rs2::stream and not rs2::pipeline), and it also does not crash, so it appears the problem is with machinery specific to rs2_pipeline_start_with_config.

For reference, I’m using the pre-compiled Ubuntu packages (version above), and my librealsense2-dkms is version 1.3.5-0ubuntu1.