said by Extide:SNR is way more important than the power level itself. With a 35db level it seems ok.
Keep some logs of the exact times it is fast/slow. See if there are any correlations (like slow in evenings/etc). Also have a look at signal levels when it is slow.
It stays slow for 2-3 days straight and then goes to normal for 2-3 days straight. All day and night. The signal levels I already posted are from right now which is slow.