[TG] [TG11] Depth value cycling up and down

[benzy]

I installed a new Raymarine instrument pack. It includes:
- ITC-5
- i70s screen
- P19 depth transducer

The depth works mostly fine, however, every now and then, a funny thing happens where the depth will suddenly cycle down to 0.0m and then cycle back up to correct reading.

It might do this 3 times in a row before settling down to the correct reading again. The cycling takes maybe 5 seconds to go down to 0 and back up again.

I've witnessed this happening in all depths.

Any idea what's going on and how to fix it?
Thanks