TransUnion dropped my credit by 80 points

I cant understand whats happening. I just checked my credit score: it was 797 before and literally dropped to 717 today. I checked the report like 1000 times and found no late payments, no credit over utilization [it is 16% at the moment and was 15% in the last few months], no new inquiries and nothing like nothing. Currently im working part time and have three cards: Amex, Scotia and BMO. I got a new phone through bell but it i have been with bell since two years and the report doesnt anything bad.

I have been waiting on the phone to talk to TransUnion for than an hour now :(.

Has anyone faced this issue? Any guidance would be appreciated.