Stuck java processes, draw() doesn't run

Hi all,

I’m having some problems with Processing 3.5.4 on Mac 10.14.6. I can edit/run/edit/run etc. a sketch a bunch of times (20 or more times) and then this will happen. It finishes executing setup(), but doesn’t reach draw(). The sketch opens at the size I specified in settings() but all I get is a blank grey window. The “java” item in the dock needs to be force quit. The IDE works fine. Every time I do this I get another one of these:

megacomputer:theapp me$ ps aux | grep [j]ava
me              3403   0.0  0.0        0      0   ??  ?E    2:56pm   0:00.00 (java)
me              3376   0.0  0.0        0      0   ??  ?E    2:54pm   0:00.00 (java)
me              3367   0.0  0.0        0      0   ??  ?E    2:53pm   0:00.00 (java)
me              3304   0.0  0.0        0      0   ??  ?E    2:47pm   0:00.00 (java)
me              3180   0.0  0.0        0      0   ??  ?E    2:37pm   0:00.00 (java)
me              3121   0.0  0.0        0      0   ??  ?E    2:33pm   0:00.00 (java)
me              2523   0.0  0.0        0      0   ??  ?E    1:41pm   0:00.00 (java)

These are all unkillable processes. I have to reboot to get the sketch to run, and then it works fine until this happens again. I’m not sure of the cause.

Any ideas what this is?