CAX30 Slow and unstable speed

My CAX30 has low and unstable internet. My 5GHz which is supposed to go up to 800 mbps caps at 351 and fluctuates from 120-351. My 2.4GHz fluctuates  from 81 to 220 mbps on my laptop.

On startup, the speed is at its max, 800 and 300 mbps respectively. But after a few seconds, it goes down and fluctuates like I said before.

I only recently installed it 1-2 months ago and this has been happening for perhaps a week. Any way to fix this?