How do you transfer your project from Archicad to TM? Do you use the direct link synchornisation option?
How did you manage to get a render in TM in February? At that time there was no Datasmith plugin to install on your Archicad 28.
Did you have an old datasmith plugin that worked with Archicad 27 that kept working with Archicad 28?
right now which version of the datasmith plugin is installed for your Archicad 28? Is it the latest one? https://www.twinmotion.com/en-US/plugins/archicad?