The result of the ST_Centroid method does not seems correct.
For the same request:
I get the following results:
- On MySQL v5.7.14: POINT(-122.88103164136591 49.25294096399097)
- On MariaDB v10.1.14: POINT(-122.88026060000001 49.24220679375)
The MySQL result seems to be the good one.
You can find attached a screenshot of the concrete case, as displayed in my application.
Sorry if the bug has been already opened, I didn't found any issue about this subject.