Problem with SM's management vlan after upgrade AP to 20.0.1


strange issue:
After upgrading our AP’s to 20.0.1 we lost our connectivity to SM’s mgmt’s VLAN.
This happened only with AP 450 and 450i, not with 450m and with SM in NAT mode.

This happens after few hours or days after the update.

Anyone else?

Could you please grab engineering.cgi from AP, when SMs are inaccessible, and share it with me @

When SMs are inaccessible, does the user data traffic pass through?