Electrical gremlins in a 2006 Prius

I'm trying to pinpoint the electrical issues that plague the Prius with 155k miles that I bought a few months ago.

The hybrid battery typically stays between 3-5 blue bars and the car mostly runs fine with slightly low mpg (30-35 mpg) and no warning lights

Every once in a while it goes crazy and I've been everywhere from zero bars and all engine lights on (triangle (O) and engine light) and the car having acceleration issues to it charging to full green bars a few minutes or a day later (it never charges full on an average day) These problems seem to be getting worse.

The car also had a weak 12v battery when I got it and leaky seams in the hatch that when tested with a water hose leaked on the hybrid battery from the left corner and into the 12v battery tray on the right corner.

When I replaced the 12v battery, the car ran really great for 2-3 days with the hybrid battery charge being consistent when I park and start the car the next day (typically between 3-5 bars, no warning lights)

I thought the issue was solved with the 12v replacement.

Now the problems are coming back and I documented the latest string of issues in a row:

Since my 12v battery is new, is this a sign of a failing hybrid battery, a parasitic drain or maybe water damage to a module or connector?