Trouble shooting EV mode button and EV light on dash

I have a 2014 Prius v with ~85,000 miles and I have two specific issues.

1. The EV light goes out even when the car is still in EV mode. I've confirmed this using the energy screen in the radio (arrows show power to wheels is coming from the motor via the battey and the engine is off) and also via the instant mpg indicator (shows 99.9mpg)
2. Very rarely can I press the EV drive mode button and the car actually lock into EV mode. This is from a standstill as well as going at low speeds with pressing the throttle pedal soft enough that I have no passed the EV mode bar on the dash. I know there several factors that control whether this can engage or not but my commute is long enough for then engine to get up to temp and for the battery to have a high SOC. This morning the EV mode button actually work near the beginning of my commute (with a pretty low SOC) but I could not get it to work again for the next 30 mins.

I have confirmed that my battery is good, I can get about a mile of 100% EV mode driving with an almost full battery and still reach the max EV speed of ~45mph

Also, this line from the manual is BS.

*: Depending on the circumstances, EV drive mode may also not be switched to in situations other than those above.

That's not very helpful.

 

This problem has continued and is random. I just went from having two 40+ mpg tanks to a 26mpg tank. This is all manually tracked.

 

I drove slightly less mpg mindfull after getting two consistent tanks in the 40s. Commute is extremely similar. I'm the only driver. Always fill up to the same first click which is between 9.8 and 10.5 gallons since I drive to E.

Never has it dropped so low into the 20s, even when I was flooring it constantly through the Tennessee mountains for two hours straight I was still in around 29mpgs.

I log every full up manually.

Stormtrooper (Toyota Prius V) | Fuelly

There is definitely something going on. The current tank started out very poorly and over the last 20 miles or so has completely flipped to being great on gas. First 65 miles were mid 20s and then it started creeping up to the high 20s for the average. I then switched over to trip B and reset it. Drove mildly aggressive for 20 miles and it's been in the 40s. Trip A average is now around 32mg and creeping up.

I'm wondering if heat is a factor since I park my car outside for work but indoors on the weekends and when I work from home. I'm in the Atlanta area and last week was in the 90s and the last couple days were far cooler.

I don't have any idiot lights warning me about motor or battery temp, but maybe I need to check on the battery fan.