Trunk problem between a PowerConnect 5224 and 3424

I have a problem regarding trunk/VLAN on a Dell PowerConnect 3424 and a PowerConnect 5224.

Configuration – 3424

• VLAN 1 (default) and VLAN 100
• Trunk on port G1 (fiber) (VLAN 1 and 100 allowed)
• VLAN 1 is automatically set as untagged and VLAN 100 as tagged

Configuration – 5224

• VLAN 1 (default) and VLAN 100
• Trunk on port 21 (fiber) (VLAN 1 and 100 allowed)
• Both VLANs are set as tagged

When I setup this scenario the VLAN 100 works just fine, but the VLAN 1 does not. Is this because VLAN 1 is tagged on one switch (port) and untagged on the other? I cannot change these settings.

I’ve tried to setup two 3424 which works just fine. Both were (default) set as VLAN 1 untagged and VLAN 100 tagged.

If it is the tagged/untagged setting that causes the problem, how do I fix it? Do I have to buy a new (newer) switch?

Thanks,

Kind regards

Kim