Transformation rates are imported in text format instead of numeric format

In several reports I import from a Matomo Cloud (default or custom reports) into Looker, I notice that conversion rates on objectives or forms are integrated in “text” format as a field in the data source. Unfortunately, Looker doesn’t allow you to change the format of these fields, and remains locked on the text format only. As a result, it’s impossible to perform calculations or display percentages, for example.
Has anyone ever encountered this problem?