WAP 371 malformed packets in 5Ghz ac

[Mmicano]

Gents, I have a weird issue with WAP371-E-K9 V01, fw 1.3.0.7

In 5Ghz AC mode I capture pcap using "administration" -> "packet capture" and getting a lot of "IEEE 802.11: Malformed Packet (Exception occurred)" and "IEEE 802.11: Tag Length is longer than remaining payload" from the SSID on that AP, checking in wireshark

If I switch radio to 5Ghz A-only and capture there will be NO malformed packets.

Initially the issue was that the ping from wireless clients on 5ghz AC to another IP is with a 700-1000ms delay.

same clients on 5ghz A-only or on any 2.4ghz do not have the issue, ping always normal. SSID is the same.

However as soon as I run capture and during running capture on any "eth0", "wlan0" ping becomes normal, after capture is finished ping has delay again.

I am able to recreate the issue any time.

Appreciate any ideas.

[Mmicano · Accepted solution]

The issue seem to be resolved by downgrading FW to 1.2.1.3.

no malformed packets in the capture

ping becomes normal all the time

I was able to reproduce the issue multiple times by upgrading FW  back to 1.3.0.7, if someone is interested at Cisco.