Switching between basemaps providers produces static maps without basemaps

Context

When using the Image Export feature, we’ve seen that switching from a Google Maps basemap to another one from a different provider (Positron, for instance) produces images with just the geometries and no basemaps.

On a first analysis, it seems that is a problem with the map instantiation (it doesn’t occur when switching the basemaps).

Steps to Reproduce

Please break down here below all the needed steps to reproduce the issue

1. Enable the static-maps feature flag.
2. Create a map with a Google Maps basemap.
3. Export an image.
4. Change the basemap (to Positron, for example)
5. Export an image again.

Current Result

The first image is exported with the Google Maps basemap, but the second doesn’t have any.

Expected result

Both images should have basemaps.

Browser and version

Any browser and version.

cc: @xavijam @alonsogarciapablo @rochoa @noguerol

[xavijam]

Taking a look right now.

[xavijam]

Finally decided with @javisantana to fix it in an easy way due to it is a specific case (change from one provider to another only happens in Builder). We will spend time in https://github.com/CartoDB/cartodb/issues/8906 in the near future 🎱 .