If you use a high amount, the score drops quickly, the day it's reported, but when you pay it off, it could take a few months to go back up because they don't know if the balance will stay low, you might charge to the limit again.

Also if you use near limit and pay in full each month several times in a 6 months period, that bank might raise the limit. But not if you usually keep the utilization low.

They need to see a pattern of high usage and full payment. But the credit report doesn't say that you paid in full because you keep a high balance.

What you could do is use high utilization every other month so the credit report shows that you are paying in full and charging more.