I'm floored that it is being so sensitive. I bet it's something to do with that bracket I installed.
I have never attempted any multi-LNBF setups but I know you may have trouble with trying to get sats that are 2 degrees apart with a dish that small. The physical size of the LNBFs may not allow you to place them where they need to be.
Would it be better to try for 91 than 89? I think with those brackets from SatelliteAV I could do 91/89, 97, and 101. I wonder if I could squeeze in 105 and 83?