How to join public channel?

Question

I'm trying to join a public Slack channel that I'm not currently in via the Slack API. Using the conversations.join method. The request appears to run fine, returns a 200 with a success and metadata about the channel, with is_member=true, among other fields. However, upon inspecting Slack, my user account is not added to the channel (even though it says "already_in_channel") and I am unable to perform any actions (such as inviting other user accounts to the channel) that would work if I were actually in the channel. Below is a picture of me looking at the channel I'm supposedly a member of.

{
 "ok": true,
 "channel": {
 "id": "[redacted]",
 "name": "[redacted]",
 "is_channel": true,
 "is_group": false,
 "is_im": false,
 "is_mpim": false,
 "is_private": false,
 "created": 1754057960,
 "is_archived": false,
 "is_general": false,
 "unlinked": 0,
 "name_normalized": "[redacted]",
 "is_shared": false,
 "is_org_shared": false,
 "is_pending_ext_shared": false,
 "pending_shared": [],
 "context_team_id": "[redacted]",
 "updated": 1754057962121,
 "parent_conversation": null,
 "creator": "[redacted]",
 "is_moved": 0,
 "is_ext_shared": false,
 "shared_team_ids": ["[redacted]"],
 "internal_team_ids": ["[redacted]"],
 "pending_connected_team_ids": [],
 "is_member": true,
 "topic": {
 "value": "",
 "creator": "",
 "last_set": 0
 },
 "purpose": {
 "value": "",
 "creator": "",
 "last_set": 0
 },
 "properties": {
 "tabs": [{
 "type": "bookmarks",
 "label": "",
 "id": "bookmarks"
 }],
 "tabz": [{
 "type": "bookmarks"
 }]
 },
 "previous_names": [],
 "priority": 0
 },
 "warning": "already_in_channel",
 "response_metadata": {
 "warnings": ["already_in_channel"]
 }
}

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