I am trying to migrate redhat 7 to redhat 8. Triedregister the server and no matter what I do, the subscription-manager list --installed

Product Name: Red Hat Enterprise Linux Server
Product ID: 69
Version: 7.9
Arch: x86_64
Status: Not Subscribed
Status Details:
Starts:
Ends:

subscription-manager register

Registering to: subscription.rhsm.redhat.com:443/subscription
Username: xxx
Password: xxx
The system has been registered with ID: 90d31246-d46d-4662-9d44-848718ac35ba
The registered system name is: xxx0000myhr.xxx.yy.gov
1 local certificate has been deleted.

subscription-manager register --username xxx --password xxx --auto-attach

This system is already registered. Use --force to override

subscription-manager register --username xxx --password xxx --auto-attach --force

Unregistering from: subscription.rhsm.redhat.com:443/subscription
The system with UUID 90d31246-d46d-4662-9d44-848718ac35ba has been unregistered
All local data removed
Registering to: subscription.rhsm.redhat.com:443/subscription
The system has been registered with ID: 3fa108af-6d61-41d3-8091-fdf0afab9a1b
The registered system name is: xxx0000myhr.xxx.yy.gov

subscription-manager list --installed

+-------------------------------------------+
Installed Product Status
+-------------------------------------------+
Product Name: Red Hat Enterprise Linux Server
Product ID: 69
Version: 7.9
Arch: x86_64
Status: Not Subscribed
Status Details:
Starts:
Ends:

sudo subscription-manager release --set 7.9

Release set to: 7.9

subscription-manager list --installed

+-------------------------------------------+
Installed Product Status
+-------------------------------------------+
Product Name: Red Hat Enterprise Linux Server
Product ID: 69
Version: 7.9
Arch: x86_64
Status: Not Subscribed
Status Details:
Starts:
Ends:

subscription-manager refresh

All local data refreshed

subscription-manager list --available --all

I see 3 Pool_Ids:
Pool ID: 2c94949085c53f9a0185d055b9901a32
Provides Management: No
Available: 15
Suggested: 1
Service Type:
Roles: Red Hat Enterprise Linux Server
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux Compute Node
Service Level: Self-Support
Usage: Development/Test

Pool ID: 2c940203823f9fd70182406a3e4e6858
Provides Management: No
Available: 15
Suggested: 1
Service Type:
Roles: Red Hat Enterprise Linux Server
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux Compute Node
Service Level: Self-Support
Usage: Development/Test

Pool ID: 2c940203823f9fd70182406a3e4e6858
Provides Management: No
Available: 15
Suggested: 1
Service Type:
Roles: Red Hat Enterprise Linux Server
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux Compute Node
Service Level: Self-Support
Usage: Development/Test

subscription-manager attach --pool=2c940203823f9fd70182406a3e486856

Successfully attached a subscription for: Red Hat Beta Access

subscription-manager attach --pool=2c94949085c53f9a0185d055b9901a32

Successfully attached a subscription for: Red Hat Developer Subscription for Individuals

subscription-manager attach --pool=2c940203823f9fd70182406a3e4e6858

Successfully attached a subscription for: Red Hat Developer Subscription for Individuals
1 local certificate has been deleted.

Why the last subscription "1 local certificate has been deleted"?

subscription-manager list --installed

+-------------------------------------------+
Installed Product Status
+-------------------------------------------+
Product Name: Red Hat Enterprise Linux Server
Product ID: 69
Version: 7.9
Arch: x86_64
Status: Not Subscribed
Status Details:
Starts:
Ends:

still can't subscribed.

subscription-manager status

+-------------------------------------------+
System Status Details
+-------------------------------------------+
Overall Status: Disabled
Content Access Mode is set to Simple Content Access. This host has access to content, regardless of subscription status.

System Purpose Status: Disabled

subscription-manager identity

system identity: 3fa108af-6d61-41d3-8091-fdf0afab9a1b
name: xxx0000myhr.xxx.yy.gov
org name: 14844318
org ID: 14844318

subscription-manager repos --enable rhel-7-server-rpms

Repository 'rhel-7-server-rpms' is enabled for this system.

subscription-manager list

+-------------------------------------------+
Installed Product Status
+-------------------------------------------+
Product Name: Red Hat Enterprise Linux Server
Product ID: 69
Version: 7.9
Arch: x86_64
Status: Not Subscribed
Status Details:
Starts:
Ends:

how to subscribe the server? It subscribed in Jan 10, 2023 and now not being subscribe any more.

thank you,
BN