In the web interface go to the section "Device status" → "Link statistics on rf5.0 interface", then left-click on the device to which the access is missing. Select "Remote commands".
In the pop-up window enter "config show". If the devices are configured via telnet, access to the remote device can be obtained with the "mint rf5.0 rcmd" command.
Make sure that the "vlan" interfaces are configured in accordance with the company's security policy (see point 1 in the figure below). The VLAN configuration process using the command line is described in the "VLAN configuration" article.
Pay attention to the traffic filtering rules in the switch group and in the "IPFirewall" subsection (point 2).
Make sure that the switch group for the device management is configured correctly (see point 3 in the figure above):
To display information about the devices included in the switch groups, use the "mint rf5.0 map swg" command.
To display statistics about the dropped/blocked MAC addresses for each switch group, use the "switch statistics" command.
Make sure that the switch group ID assigned for management on the local device matches with the switch group ID on the remote device. Make sure that the rf5.0 interface has been added to the switch group. The svi interface must be associated with the switch group and its IP address is used for the management of the device. For detailed information about the device management configuration proceed to the "Remote management of the R5000 units" article.
Pay attention to the traffic filtering rules in the switch group and in the "IPFirewall" subsection. Make sure that the traffic from the remote device is not restricted.