Slack opens browser as slack instance if browser isn't already open

I have the latest Slack version through snap.

installed: 4.9.1 (28) 144MB classic

My issue is similar to this, but if I have Firefox open already, a new tab is opened correctly. If Firefox is closed, then a new app in Slack is opened.

I followed the other question's answer and checked about:profiles, but only have a single profile there:

I would like to avoid downloading specific version packages, if possible.

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