Hamster stopped using wheel

[Pumpkin95]

Hi everyone! I'm new to this forum and am a first time hamster owner. I have a very active golden syrian hamster, 16 weeks old. She is currently in the rosewood pico XL cage which has a few treat and chew toys, bridge, and 2 tunnels. I noticed that she kept biting the bars at night and after some research found out that her wheel which came with the cage was too small. So I got her a 8" trixie wheel (anything bigger won't fit in the cage) and she really took to it! She was crazy and used it for 2 days straight! I noticed she didnt bite the bars at night. But one day she just stopped using it and now its been 1 week and she still hasnt used it. She either hesitantly goes in the wheel but doesnt use it and comes straight back out, or she uses it for 2 seconds and that's it. There isnt anything wrong with her illness-wise, she is very much active in the hamster ball and I haven't changed anything in her diet. I was just wondering if this is unusual behaviour, how to stop the cage biting and encourage her back on the wheel? I have tried placing treats in the wheel but she just reaches inside to grab them without using the wheel. Any suggestions/advice?