Will involve a little pain, but may be your problem as what you describe is very similar / almost identical to the issue I had.
The Ignition wires go down under the LH fairing into a bank of 4 connector blocks covered with a plastic shroud. The plastic shroud is wide open at one end and tight at the other end. Logic would dictate the the open end would face toward the rear of the loom. Alas, this was not the case, resulting in road crap sealing the tight end and creating a funnel for water to sit in. The ignition wire was slowly corroding which creates brief intermittent loss of complete electrical power only to be restored a split second later. Eventually, the wire completely seperated from the plug, resulting in no power to the dashboard or the other systems leaving you stranded at the side of the road awaiting recovery DAMHIK.
Remove the LH fairing and check out the state of the wiring into and out of the bank of plugs.
This is the item to check...
Cheers