I own a chinese YF PND with wince 6, GMXT ver 5.00.20wp has run smooth on this PND for years without any significant problem

Recently I change the original launcher application with IPhone like launcher, now my GMXT behave strangely

On every startup, GMXT would scan the attached gps device for a long time then failed, the only way to fix this, is to disable the gps, choose serial port com 1 and re enable the gps, then it works as usual

It's very annoying to disable, then re enable the gps on every startup

If I switch back to the original launcher, the problem gone

Can anyone help me ?