Transmission problem

Very pleased to receive this, my joy is now well dimmed because in a few months, the two probes of plants, and now the outer probe report more information on the weather station. The displays of probes are always operational, but more transmissions. Is this comes probes that emit more or weather station that receives no more? My disappointment is there anyway.
PS: I wake up with the same brand external probe that also report more information in recent weeks. Coincidance or quality problems with the fabriqcant? You decide!