High availability (carp, pfsync) problem when 2 opnsense are connected on cisco

[ict.support]

Hi guys,
Sorry for my English, but my language is french.

I have a problem with the operation of 2 opnsense configured in high availability mode.
When Lan network cards are connected to my Cisco switch, the network is severely disrupted.
I followed the documentation from the wiki for configuring high availability.
Thank you in advance for your suggestions.

Didier