The only though I have that could be car related is that the ICCU is on its way out and has increased it’s resistance requiring that little more power to maintain its charge rate but it’s highly unlikely. From everything I’ve read on the subject it’s either working perfectly or failed completely, suggesting something before the car is your problem. @kezo is your best bet zeroing in on where that could be.
I suspect the OTA update is coincidental.
I'm Autistic, if I say something you find offensive, please let me know, I can guarantee it was unintentional.
I'll try to give my honest opinion but am always open to learning.
Mark