I'm sorry I believe my initial understanding was wrong. The time frame is still correct but I thought it was feeding but after you asked this it made me doubt myself and upon looking it up it's a different reason.

They feed immediately but it appears that it is contingent upon when the tick starts having to get rid of excess water. Until the blood meal has started to engorge the tick, though, the organisms are not activated in the tick's gut. So until you see that the tick has actually engorged a slight amount, it's apparently not enough for you to catch disease from the tick.

https://www.uptodate.com/contents/what-to-do-after-a-tick-bi...

Again, sorry for the incorrect info initially!