Topology change every 1h

[Adam]

Hello together,
we have a big problem on our network, topology change takes place every hour and in the morning sometimes every 3 minutes.
We use RSTP and BPDU on all edge Ports.
We have 2 Core S8 and about 50 Stacks with B2, B3 and B5, altogether about 150 Enterasys switches.
Both S8 are with 2x10Gbit connected together to a lag.0.1 with all vlans

First S8 is the Root Bridge

Designated Root Priority - 4096
Designated Root Cost - 0
Designated Root Port - 0
Root Max Age - 20 sec
Root Hello Time - 2 sec
Root Forward Delay - 15 sec
Bridge ID MAC Address - xx
Bridge ID Priority - 4096
Bridge Max Age - 20 sec
Bridge Hello Time - 2 sec
Bridge Forward Delay - 15 sec
Topology Change Count - 24778
Time Since Top Change - 00 days 00:35:02
Max Hops - 20

Second S8

Designated Root Priority - 4096
Designated Root Cost - 1
Designated Root Port - lag.0.1
Root Max Age - 20 sec
Root Hello Time - 2 sec
Root Forward Delay - 15 sec
Bridge ID MAC Address - xx
Bridge ID Priority - 8192
Bridge Max Age - 20 sec
Bridge Hello Time - 2 sec
Bridge Forward Delay - 15 sec
Topology Change Count - 24755
Time Since Top Change - 00 days 00:35:02
Max Hops - 20

Our Problem is that the Topology change doesn´t match all Stacks, there are only 17/50 and both Cores which are doing that. We disabled the complete redundancy and it still happens even there where only one stack is connected to both Cores...

How can we find out who causes this Topology change?

All other topics here didn´t help us.

Thanks for help
greets

[Bill_Handler]

He has stated that he is using Enterasys S8, B-Series Switches. They do not have ELRP. Only the Extreme Branded (Purple) switches have ELRP.