WiFi off slows down getting back to home screen

[ReaLx3m]

I have the wifi off most of the time, and kind of didnt notice any difference in performance for quite long time.Up untill yesterday.
With wifi off, getting back from a book/comic takes about 3-5 seconds, but when turning wifi on and the reader does its sync(automatic sync is off), returning to home screen is instant.Even if i turn off wifi after the sync, it continues to be instant for few more hours, and then it slows down again(i suppose when its time to sync again but no connection is available?).

Using H2O with 4.12.12111 firmware.
I dont think patches are the culprit, but here is what im using just in case:
Increase the cover size in library
Increase the view details container size
Increase size of kepub chapter progress chart
Remove footer (row3) and increase cover size on new home screen
Dictionary pop-up - increase available text area
Fix reading stats/author name cut off when series is showing
Both page turn sides go next
Custom font sizes
Freedom to advanced fonts control
Set KePub hyphenation
Change dicthtml strings to micthtml
Always show confirmation dialog before upgrading
Fix three KePub fullScreenReading bugs
Allow searches on Extra dictionaries
Dictionary, remove long winded closest match notification
Replace adobe page numbers toggle with invert screen

Anyone experiencing similar behavior, and is there any idea for a workaround without having wifi on all the time?