This is a bug. I can't create a Summary field (Total, Avg, etc.) of a Calculated Value field. But if I change the CV field to a Number field, I can create its Summary field, and I can then change the Number field back to a Calculated Value field.
I suppose it depends on the TYPE of summary. I would think Total of would not work with a TEXT, but Count of would.
It's a little dangerous to change a field type like this.
Calculated Value = auto-enter calculation?
or are you describing a field of type calculation?
With a field of type calculation, you'd need a number result type for summary fields that require number type (total of, average....)
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