Mesh 802.11s encryption does not work

Hi
OpenWrt is an amazing project I've been using since 2015.
My experience has been flawless so far, until today when I got a new router expecting to set up a mesh (802.11s) network.

I have two TP-Link Archer C6's running the latest stable release (OpenWrt 19.07.3 r11063-85e04e9f46)
I'm following this guide to set up my mesh, and it works fine when using 'encryption = "none"'. Both peers connect and show up as ACTIVE at the wifi station dump

However, when I try to set up encryption by passing

config wifi-iface 'mesh'
        option network 'mesh'
        option device 'radio0'
        option mode 'mesh'
        option mesh_id '<your-mesh-name>' 
        option encryption 'psk2/aes' # I have also tried psk2+ccmp, without success.
        option key '<your-secret-password>'

both peers won't connect. The interface goes up and seems to be running, however I see 0 TX RCV bytes and no information being output by

iw dev <interface> station dump

Am I doing something wrong? Is 802.11s encryption supported by OpenWrt?

Thanks in advance!

EDIT:
After checking logread, I noticed that wpa_supplicant was throwing errors as it was not recognizing the key_mgmt=SAE parameter as valid. I have removed wpad-mesh-openssl and installed wpad-mesh-wolfssl. After a full reboot the mesh peers connected and encryption is running fine with the provided config.
Thanks