Edge 830 firmware update has broken power

I have had my Vector 3 single sided pedals since September last year. 

I have been lucky enough to have had absolutely no problems with them. 

I am awaiting the new doors but the ones that came with my unit have given no problems. 

When I first changed batteries I used the single ones rather than the two batteries.  Again these have been no problem. Presently my Edge reports batteries as being "good ".

Then came the updated firmware,  5.5 for my Edge 830,  since then I have experienced constant dropouts and some occasional spikes on the three 4hour rides. 

I have posted on this on the Edge 830 forum as well. 

Occum's razor would lead me to believe Garmin have introduced a bug into this firmware rather than it being any problems with the Vector but just in case...

What do folk think?