VLAN assignment delay to take effect

[ABUELKHAIR]

I have fortigate 81E and i have 3 Switches S248EF 

one connected with SFP to the fortigate and 2 with Ethernet 

All of them directly connected to the fortigate 

Created my VLAN's 

When we assign a vlan to port of the switch for switch 1 using the SFP is working fine with no issues 

When we do the same for the the other 2 switches i can get the IP address, mask, and gateway but i cant ping my gateway. it will take 4 min connected with no activity then it will work 

I don't know all the switches having same software same config 

Any ideas 

[emnoc]

Possibility 

1: did you rule out bridge loops or are these 3 switch not connected together

2: are the fsw software updated 

3: what does any stp logs show if any 

 exec log filter clear 

 exec log filter field subtype spanning-tree

 exec log display 

I would start with those 3 things and look for any critical errors if any.

Ken Felix