Try to up your temp or set your temp a bit higher, run a temp of 78 or as close to it as you can will give you the best growth. In flower if you can you can lower temperatures go ahead by 5-8 degrees but if you can’t then no sweat I leave mine the same the full cylce with great results.
Before you start messing with your humidity print this off and put it in your grow room, it’s a VPD chart.
If you want to learn about FIM’ing here