How low does your download speed go ? , any Openreach FTTP PON is a shared medium, you and upto 29 others on the network ( often it’s a much lower number sharing the bandwidth ) , but ultimately the members on the PON all share a download bandwidth of 2.4Gb , if there were 30 users and they all simultaneously were downloading large files that’s ‘only’ about 80Mb each ( although it’s not quite that simple as that ) but the point is , if you happen to be on a PON with a few intensive users ( downloaders ) the bandwidth available may dip below the minimum speed guarantee, although the bursting nature of data transmission and DBA ( dynamic bandwidth allocation ) means it shouldn’t be a big problem, hence asking how low the speed gets .
If this is the case ( congestion ) and you unfortunately have a few bandwidth hogs on your PON , there isn’t a lot that can be done about that , you can ask to released from any minimum term penalty free ,if this below minimum speed is observed frequently, however unless an alternative network is available, I’m not sure what that would achieve, a different provider on same PON would have the same issue.
If it’s not just congestion ( and it may not be that ) , it’s difficult to see why that would only be apparent occasionally rather than all the time .
