The fact that the EBOX speedtest shows poor performance too. Perhaps the FTTH splitter your sharing with neighbors is oversubscribed? I recall hearing that all 3rd party FTTH is put on a separate splitter from those of Bell customers.
On a side note I have noticed consistent full speed test results with bell while the others seem to be all over the place during primetime.
Fibrenoire tests seem to go out via Bell transit, Cooptel via QIX so thats not the issue. Of course we don’t know the return path…