Supposedly, an average score shouldn't go up or down much on a single game or even a bad day ... but when mine will go up 8 strokes and then only crawl back down, there is a problem.
Your average is a waited score based on a series of results from game play. I don't know exactly how many games are involved but some of the members here do, and they can explain it better.
You've recently changed tiers, it'll settle down soon.
Once you change tiers your average scores are only the ones at your new tier. Until you have about 20 rounds posted they will jump up and down a lot especially if your rounds are 36 and 44 for nine holes.