I experienced similar slower speeds a few months ago, also after a thunder storm. Syncing 8000 mbps as opposed to 22000 mbps. Did some extensive testing through the phone with Support and had a technician come out.   There was some errosion on my phone socket, but turns out the issue was with my modem all along. After ordering a replacement (of the same model) - back to 22000 mbps again :)   Would recommend you try with a separate modem if possible and see if your milage varies. I didn't believe storms could affect modems but this really was the case. If a separate modem yields similar results, might be your phone line/connection/socket etc. ... View more