I am getting similar WebGL error messages when switching CARTO VL visualizations:
[.WebGL-0x59c22054800]RENDER WARNING: there is no texture bound to the unit 0
[.WebGL-0x59c222e5500]RENDER WARNING: there is no texture bound to the unit 1
These errors are being returned when switching from a current visualization to a new created one as shown in this example, but also when blending the visualization with a new filter as in this other example.
I have seen the last option working fine in this block. What is wrong with my examples code?