Throughput issues to home devices

I recently switched to 2Gb service and I can't get anything over 200-600 Mbps except on my laptop, which will get 1Gbps, but not sustained it usually falls back to 750Mbps. A tech came and swapped my XB7 to XB8 modem/router, but It didn't help. He did show the speed coming to the modem was 2100-2430Mbps, but none of my devices are getting near that. I just added a Deco mesh system and switched the router to bridge mode, and it didn't make a difference at all. I feel like my internal devices are being throttled by something. Last month, every device in my house was getting 1.2-1.5Gbps, something changed.  Please help.