Nope, you are not delusional when you fired the M1 (PF) round and it did nothing, it is actually that bugged. The G6’s proxy fuse round is still bugged after 2 years of bug reporting. It’s even more detrimental now that the disabling/enabling fuse feature is implemented.
https://community.gaijin.net/issues/p/warthunder/i/DIFHS6DsfEMK