Coot glitches with transparent surfaces in fancy mode

Hi Paul,

If I switch on "fancy" mode in the shader settings, and turn off SSAO, I see some weird glitches - yellow criss-crossing planes - that appear when I rotate the view:

https://www.dropbox.com/scl/fi/s40yf389gmu1aacek6bf7/coot_glitches.mov?rlkey=qfn6iqlc2kddpbe9m4ovxyuq1&dl=0

This is using 1.1.20 stable, on Mac OS Sequoia.

Cheers
Oli