Vector Tile Labels Disappear with changing active layer

[palmerj]

Describe the bug
Vector Tile labels disappear with changing active layer to another layer.

How to Reproduce

1. Start a new project, then add vector tile layer. e.g MapTiler endpoint
2. Add another layer to the map.
3. Change the vector layer to add a label style
4. Check the label shows on the map
5. In the layer tree select the other layer. Vector labels disappear

QGIS and OS versions

QGIS version	3.14.0-Pi	QGIS code revision	9f7028f
Compiled against Qt	5.12.3	Running against Qt	5.12.3
Compiled against GDAL/OGR	2.4.1	Running against GDAL/OGR	2.4.1
Compiled against GEOS	3.7.2-CAPI-1.11.2	Running against GEOS	3.7.2-CAPI-1.11.2 b55d2125
Compiled against SQLite	3.28.0	Running against SQLite	3.28.0
PostgreSQL Client Version	11.3	SpatiaLite Version	4.3.0a
QWT Version	6.1.4	QScintilla2 Version	2.11.1
Compiled against PROJ	5.2.0	Running against PROJ	Rel. 5.2.0, September 15th, 2018
OS Version	macOS 10.15
Active python plugins	QuickWKT; qgis-maptiler-plugin; processing; db_manager; MetaSearch

[palmerj]

Thanks @nyalldawson