@Scootmaster welcome here!
You read out 18V after your regulator at the battery, right? Blows bulbs?
Then you can say with a 99% accuracy, it's the regulator/ rectifier. An very common and known issue on many modern motorcycles.
(pls see link)
https://www.kymcoforum.com/index.php?topic=33615.0Had the same issue on several scooters lately. Take any reg/rect (brand) which you can get. Some last longer, some shorter and are inexpensive. Internet platforms offer plenty from €28,- to €42,- all pretty much the same.
It's not worth the work to open, clean out, change burned diodes and EC.
You can take any reg, also from Grand Dink/Yager 250 or...etc.as long as they have 3 yellow and a red and black cable.
Very easy to change, two 10mm nuts hold it in place, goes without removing sidepanel.
For our 500th is the standard 5 cable (3 yellow, from generator, 1 red 1black to battery) the right one.
After that you might change your halogen H4 bulb to a fancooled LED H4 and LED position lamps, has some benefits.
Maybe give us a feedback to learn.