Modern Vespa

My injection telltale light (Engine lamp) start suddenly to glow when I raise my rpm. I have been looking around and I see the reason can be the voltage regulator, but before I want to change it I will tell little about the time from last autumn to this spring.
Scooter is standing inside and was parked last October with full gasoline tank.
Two times this winter I have been charged the battery. The clock was not working when parked, so in February I demounted the instrument panel, change the small battery inside and the clock was again working.
Three weeks ago I change engine oil, filter, oil in gearbox, and some other small things. Then I saw the clock was flickering
(now readable numbers, just some strange figures)
When I was going out for my first ride the Engine lamp start glowing when I raised the rpm. The clock did flickering in beginning, but after short time it was no sign for anything there.
I have measured the charging at battery when raising rpm to about 3500-4000 rpm and I have about 16V. That is of course to high, but I wonder can it be that I has mounted one of the contact on the instrument panel not 100% right?
Does it have to be the voltage regulator?
Everything else works normal.

That is DEFINTELY the regulator. Change ASAP as it is killing the battery.

When I look at the electric sheet I see the only possible fault is the Voltage Regulator.
New regulator is ordered

Ordered a regulator from AliExpress. It arrive a couple of days ago. I change it yesterday afternoon, and now the charging is back to normal and the lamp is not glowing up under driving