Reimport mesh video memory leak

UE 4.26.2 after many times reimporting (~ 9-10 times) the same mesh editor is crashing.
(ERROR: Out of Video Memory Trying to Allocate a Texture…)
With each subsequent re-import, the video memory consumption increases.
I reimport a building (have 203 parts, ~103k triangles in total). It is in on modeling stage. Export this as a single mesh in Unreal Engine and turn on the option: combine meshes.