In-line Fan with 2 switch lines

[Kinxsize]

Did anyone fit a Vent-axia Multivent MVDC-MSH or similar fan with 2 switch lines.
So I have bathroom and a tea point. Both of the same in-line fan. I have connected each of the independent switch lines to dedicated Sl1 and Sl2 terminals in the fan. Unfortunately when in one room lights are on then straight other room light on to troughs the Ls . If somebody knows how to correct connect that I would be greatly appreciated.

 

[freddo]

The 2 inputs are separate and there should be no interlinking between SL1 and2 If there is there has to be a wiring error or a fault with the unit. IIRC the inputs are both opto isolated so any internal interlinking between the 2 should be impossible. Check your wiring carefully again.