Can two Root Bridges in a Network Cause Issues with Vlans

Hi guys,

We have 3 switch stacks across 3 floors in our building. I have created a vlan 240 SVI on 3rd switch stack 10.100.240.1 and then created the 240 vlan on the 1st and 2nd stack. For this purpose I have extended the Vvan via connecting the switches via a 240 access port. Switch stack 1 and 2 both connect to the 3rd switch stack.

When I add a machine to the 240 vlan on the 3rd stack and on the 2nd stack the machines are able to communicate. However when I add a machine on the 1st floor stack it is unable to communicate with other machines on the vlan and vice versa.

I have checked the status of the vlan which is up and the link from the 1st to 3rd switch stack is up as I am able to ping the vlan 240 SVI from the 1st switch stack.

I have checked STP on all three switches stacks and I have noticed that there are two root bridge switches. The first is a root and so is the 3rd. All switches have default priorities so based on MAC address the 1st stack should really be the root bridge.

Anyhow besides all that my question is if this can be causing the issue I am having with vlan 240 on the 1st switch stack and what is the best way to resolve this? Thanks.