Following up on this, I found this gem in the MySQL docs:
“By default, geographic coordinates (latitude, longitude) are interpreted as in the order specified by the spatial reference system of geometry arguments.”
- https://dev.mysql.com/doc/refman/8.4/en/gis-wkt-functions.html
So it seems that the WKT for a point isn’t always POINT(x y) and I need to look up the order that WGS 84 expects.