You should wait for the statement to pay your spending instead of covering it same day. Otherwise it’s not reported to the credit agencies and it looks like you have no activity on your card.
Also, generally speaking some fluctuation from month to month is to be expected. I wouldn’t worry too much about 10 points in either direction.
Exactly. 10 points is nothing and you’re better off building longer term credit (on-time payments) instead of short term credit (reducing credit usage) unless you’re looking to use your credit in the next month or two (get a mortgage, auto loan, or credit card).