yes same problem here via talktalk fibre had BT engineer out twice but has never came into house because of covid restrictions , so he just reset DLM.My speeds at home aren't good enough for IPTV, especially when 2 or 3 people are using internet, PS5, YouTube etc.
We should be getting 28Mbps minimum according to BT test but at the moment 13.4 Mbps and most we ever got was about 21 Mbps a while back just going through the routine 30 days then think will apply downstream handback threshold rule.