I experienced this for the first time. I was flying in the Caravan without cargo pod, with no GPS, VOR to VOR.
[image: 5b593bd9-5172-4279-846a-ba4bf391b734.png]
At #1, it switched to ROL for the first time. It took me a while to realize what was wrong, but I was eventually headed in the right direction. Then it switched to ROL again, by #2. Back on track, and no further problems. As I flew over the VOR (#3), it switched to ROL, but this is, as I understand it, the correct behavior, when briefly losing the signal.
As I was slightly adjusting the heading away from the VOR, I had an idea. The first two times it switched to ROL, the heading bug was still pointing north, as thas was my takeoff heading. After the second disconnect, I finally centered the heading bug, and had no problems after that. So I now set the heading bug 90° to the right, just to test. It again switched to ROL at #4. I, yet again centered the heading bug, and I reached my destination without any more disconnects.
Anecdotal, of course, and it might be purely coincidental, but for all my unexpected switches to ROL mode, the heading bug was not centered, and while it was centered, I had no switches. Further testing needed.