10Mhz (5Ghz band) channel increases distance/ack??

RouterOS Wireless Networking
1

I have this rb532A running 5.0rc12 in normal 802.11 mode.
I narrowed the band to 10Mhz to free a bit of spectrum.

But now I see two weird effects:

  1. Signal strenght of very close units, but lower then Omni of AP, are getting poor signal now.
  2. Distance (or Ack) is much higher then real. 50 mtr unit show 3km, 400mtr unit shows 4km etc. In clients themselves same effect or high ack times, 35+!

Can this have anything to do with the use of 10Mhz? Or is this a result of the use of the nv2 package? Or is it the rb532A?
I have a rb333/ros5.0rc12 20Mhz channel/802.11 where distances are correct to real.
I have a rb433AH/ros5.0rc12 10Mhz channel/nv2 where distances are correct too.

2

Probably this was the result of too strong a signal coming from the omni antenna. I lowered the power output and the problem was gone on the CPE.
Then I put the output at default again (needed for distant client) but made sure this close range CPE only made contact with AP on the transmitted centre frequency (it also picked up adjacent freq. of that AP transmitter, with low signal levels) and the problems was solved.