Fibre syncj vs throughput

I have had a fibre connection for some 3 months now and initially it was perfect. My connection is 40/2 and I generally get 37/1.9, and that is ok for me. However after a couple of weeks the peak period downloads dropped to about 7, uploads were still ok. Some changes were made at the exchange and things improved for awhile. My provider keeps telling me that the synch speed reports a 40Mbps second and that throughput cannot be measured by them ! So I am confused.if the synch is 40, why am I getting a much lower throughput, for example something in the order of 10.

Any thoughts would be most appreciated.

Ensure you are also registered on the TBB main site - you can use the same name however registration and logins and separate.

Then run some speedtests from there and they will be linked to your profile. When you view a speedtest there are a set of links below, select the appropriate one and post the link here so that others can see what is happening and comment.

As well as that, are you able to see your modem stats? If you can, post the key ones: Sync speeds, Max attainable, SNR and Attenuation figures as a starting point.

Who is your supplier? Which exchange are you connected to?