Acoustical Acoustic Panel Accessories

Reduces sound level but problem staying up

There is no doubt that the panels have attenuated the echo but I have other problems to resolve now. We used the recommended adhesive for the panels which are on the ceiling but two have now come down twice now. I must reveal that the panels are located in a garden room, which is subject to considerable diurnal temperature variation. I am now having to consider a physical suspension system and the difficulties associated with these are yet to be resolved. I am debating if I can get away with three rather than four per panel. Also we have adhesive residue on panels and ceiling. Can these be overpainted?