Ring Doorbell pro goes offline after a few hours evey day

Hi Would be grateful for any assistance regarding the query below. I have had a hardwired ring pro doorbell for nearly 3 months, was working fine for a month but since then, it goes offline everyday in the afternoon from 15.00 onwards and will not go online again until early the next day. The voltage is always over 4000 mV, firmware is upto date. I have been onto the helpdesk and they have sent me a transformer as this is what they believe the problem to be. I have not yet tried this as yet as not sure how this would solve the problem as it works until late afternoon. Does any one have any suggestions as to why the doorbell goes offline everyday after 15.00 hours. Have never any problems with the chime going offline. Many thanks in advance Kets