Substance for Blender 3.1.0 fails after save and reopen

The plugin fails when saving a blender file that has a substance-based material, exiting and restarting blender, and attempting to make any changes to the parameters. This error is issued:

Substance 3D addon for Blender: “The rendered substance graph [Nero Marquina Marble] was not found.”

(Obviously, the .sbsar used in this case is nero_marquina_marble.sbsar but it appears to fail with all .sbar’s)

This is printed in the blender system console on file load:

Substance 3D addon for Blender: [INFO] Dynamic class [SUBSTANCE_GRPH_3BBAB430-381C-454F-9C55-81D22A5D03E9] for graph [Nero Marquina Marble] created correctly
Substance 3D addon for Blender: [INFO] Substance file [D:/Documents/SL/Blender/Assets/Substance Source/Marble and granite/nero_marquina_marble.sbsar] was preloaded succesfully
00:06.719  operator         | Substance 3D addon for Blender: Substance Tools Connect Success [0.0075 seconds] - Application [Blender] with process id [28232] and port [53888] is already connected
00:06.719  operator         | Substance 3D addon for Blender: Addon  Server Start Success - Substance Addon Server already running in port [53888]

This is printed when attempting to change one of the parameters, e.g. resolution:

00:38.500  operator         | ERROR Substance 3D addon for Blender: The rendered substance graph [Nero Marquina Marble] was not found

Windows 11 Pro 24H2 / 26100.9711

Blender 5.2.3

Plugin and integration tools both 3.1.0, reinstalled from scratch.

This error has been present in many previous versions as well.