Is this normal for the fuel gauge?

Its probably loose at its connections to the printed circuit board. Factory used stamp tin speedy nuts there. a little vibration or temp change will make or break the connection.
Depending on what panel you have and your ability you might reach up in there with a 1/4 drive disc ratchet and 3/8 socket to tighten the nuts a little.
Any way you go about it disconnect the neg' battery cable first.