v25.3.1, alpha errors "Please retry again, server is not ready to accept requests"

Describe the bug

we deployed 3 learner alpha pods.
Sometime one of learner alpha is unable to accept query requests and returns the following error: "Please retry again, server is not ready to accept requests"."
and /health?live=1 returns 200, but health returns 503.

http://localhost:8080/health, 503 Service Unavailable, "Please retry again, server is not ready to accept requests"
http://localhost:8080/health?live=1, 200

[
    {
        "instance": "alpha",
        "address": "dgraph-learner-alpha-0.dgraph-learner-alpha-headless.svc.cluster.local:7080",
        "status": "healthy",
        "group": "1",
        "version": "v25.3.1",
        "uptime": 285560,
        "lastEcho": 1777346016,
        "ee_features": [
            "backup_restore",
            "cdc"
        ],
        "max_assigned": 2206421499
    }
]

http://localhost:8080/probe/graphql , 200

{
    "status": "up",
    "schemaUpdateCounter": 0
}

alpha learner logs

E0428 03:09:49.515381       1 draft.go:1458] While retrieving snapshot, error: cannot retrieve snapshot from peer: rpc error: code = Unknown desc = operation opSnapshot is already running. Retrying...
I0428 03:09:49.515447       1 draft.go:124] Operation completed with id: opSnapshot
I0428 03:09:50.505477       1 draft.go:198] Operation started with id: opRollup
I0428 03:09:50.515906       1 draft.go:198] Operation started with id: opSnapshot
I0428 03:09:50.515973       1 draft.go:124] Operation completed with id: opRollup
E0428 03:09:50.516338       1 draft.go:1458] While retrieving snapshot, error: cannot retrieve snapshot from peer: rpc error: code = Unknown desc = operation opSnapshot is already running. Retrying...
I0428 03:09:50.516390       1 draft.go:124] Operation completed with id: opSnapshot
I0428 03:09:51.506878       1 draft.go:198] Operation started with id: opRollup
I0428 03:09:51.517209       1 draft.go:198] Operation started with id: opSnapshot
I0428 03:09:51.517313       1 draft.go:124] Operation completed with id: opRollup
E0428 03:09:51.517723       1 draft.go:1458] While retrieving snapshot, error: cannot retrieve snapshot from peer: rpc error: code = Unknown desc = operation opSnapshot is already running. Retrying...
I0428 03:09:51.517794       1 draft.go:124] Operation completed with id: opSnapshot
I0428 03:09:52.508172       1 draft.go:198] Operation started with id: opRollup
I0428 03:09:52.518652       1 draft.go:198] Operation started with id: opSnapshot
I0428 03:09:52.518756       1 draft.go:124] Operation completed with id: opRollup
E0428 03:09:52.519080       1 draft.go:1458] While retrieving snapshot, error: cannot retrieve snapshot from peer: rpc error: code = Unknown desc = operation opSnapshot is already running. Retrying...
I0428 03:09:52.519102       1 draft.go:124] Operation completed with id: opSnapshot
I0428 03:09:53.509970       1 draft.go:198] Operation started with id: opRollup
I0428 03:09:53.519332       1 draft.go:198] Operation started with id: opSnapshot
I0428 03:09:53.519421       1 draft.go:124] Operation completed with id: opRollup
E0428 03:09:53.519768       1 draft.go:1458] While retrieving snapshot, error: cannot retrieve snapshot from peer: rpc error: code = Unknown desc = operation opSnapshot is already running. Retrying...
I0428 03:09:53.519795       1 draft.go:124] Operation completed with id: opSnapshot
I0428 03:09:54.510889       1 draft.go:198] Operation started with id: opRollup

Expected behavior

alpha works normally

Screenshots

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Environment

dgraph v25.3.1 with learner alpha

Additional context

Add any other context about the problem here.

Start in draft.go around the logged lines 1458, 124, and 198, then inspect how the learner handles snapshot and rollup operations. Reproduce the v25.3.1 learner-alpha condition and compare /health with /health?live=1; done means the alpha accepts requests and reports the expected health status without repeated opSnapshot errors.