Interesting cold weather fuel gauge behavior

[Kira]

This regards a 2007 Volvo V70 (base) @155k; my DD.

I filled the tank at the start of the current, deep cold spell and parked it nose down. SOP.
The fuel gauge read "all-the-way-full" for 11 days over 250 miles of local driving.
Just now, arriving home from grocery shopping, the gauge is where it should be.

I believe what happened was that the float was as high as it could go and that the deep cold affected a dimension of something in the tank.
Perhaps the metal float rod, or a bushing on which it pivots, was able to jam against something or just plain stick?
For the last week, I would occasionally stab the brakes whilst rolling forward or backwards to free the float with sloshing fuel.
I wish I had seen it free up.

I post this because I've never experienced this over 60 cars, both mine and family.

An annual dose of Techron or Red Line DS-1 fuel system cleaner is the only non-gasoline thing ever introduced.

 

[K-Man]

Had this happen during warm weather in a rental car in California years ago. The car was a Plymouth Sundance 4–door with about 10,000 miles. After nearly 200 miles on the Interstate without the fuel gauge moving off "F", I lightly thumped the glass in front of the gauge and it settled to the true reading, which was just above halfway. The gauge worked normally after that.

Maybe it's worth trying this next time.

 

[Kira]

Thumping had no effect.
The gauge would always drop immediately to E upon shutdown -and shoot up to F at startup- so I didn't think the needle was sticking.

I had, just the month before, reinstalled the cluster after a refurb. I used Upfix in Georgia.
I was wondering if the1 year warranty would see me back to the UPS store.