My understanding of the error is that it's in relation to corrupt of unexpected packets during the EAPOL 4-way handshake between the WAP and the RADIUS server. This could be anything from drops, discards or error on ports between the WAP and RADIUS server to firmware bugs etc.
I'd suggest working with Meraki support on this.
Additionally, understanding how many WAP's are impacted and if there's any commonality between those that are impacted (Eg. same switch, same firmware, same model) will help with the troubleshooting.