| I have had some phal leaves with similar spots over the years and they seem to develop then do nothing with the leaf surviving and apparently functioning normally. There are some fungi that make little rings like this.
I tend to be conservative in treating these, especially in a case like this where the "condition" does not seem to be advancing or life threatening. My approach would be to watch it and use no or minimal intervention unless something changes. Some folks here on the forum will disagree and prefer to treat aggressively and intervene with fungicides. Maybe wait for some of those second opinions and then decide. It looks like there's no emergency.
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