Link speed is only 54Mbps for AC client (5GHz)

Hi,

I'm using Netgear R7000, 5GHz AC1900 (Max 1300)
using Macbook Pro 16' (but same issue seen also using Macbook pro 2016 & Ipad pro 10.5)

There was no issue till today - I get only 54Mbps in the link for the 5GHz.
PHY is 802.11ac , RSSI is -36dbm , Noise is -95dbm (80MHZ) so it doesn't seem wireless issue.

I assume its something with the router .
Both 2.4GHz & 5GHz are enabled. Qos is disabled , WMM is unchecked. (reboot didn't help.)
Didn't try factory reset.

Any idea what can be the problem ?

Thanks in advance,
Shaul.