Fan behaviour

I have 3 Manrose fans in the house - two non-timer models and one timer model. All 3 have isolator switches present outside the room they are installed in.
The timer model behaves as I expect - comes on when light turned on, remains on for 1 min after light is turned off.
The non-timer models are controllable only through direct use of the isolator switch - using the light has no effect on them. Is this normal installation?
Many thanks.

depends who specified them as to what they are supposed to do. but normaly the answer would be no. they are wired direct not through the light switch

Ok, many thanks.
This means that since my wife is too short to reach the switch, I'll get her summoning me each time she's finished in the shower. Oh joy.