No real suprise.
The unofficial transfer window usually opens directly after last PL game in mid May, (although registration of new players can only happen from 30 June) and ended just before the season started in mid August (brought forward from previous seasons) - so in practice a full 3 months.
So the TW is starting later (due to PL finishing later) on 27 July and finishing on 5 October (or a week later for EFL transfers) so actually its a shorter TW than usual !