Hello Tracey Sharples,
Do you tried to disable graphics override ?
Do you change your model view ?
Do you check your 3D view options ?
Have a great day,
Christophe - FRANCEArchicad Designer and Teacher
Archicad 15 to 27 FRA FULL
OS 11.6 Big Sur - MacBook Pro 2017 - 16Go RAM
"Quality is never an accident ; it's always the result of an intelligent effort" John Ruskin