MacOS Security Update caused mex files to stop functioning

I have a program in matlab that uses the msocket toolbox from many years back now. I am on a 2019 Macbook Pro running Mojave. When i first moved the program onto this laptop I had to compile the mex files for maci64 for the first time. I compiled them using R2015b. They worked great for about half a year no issues until I paused my research activities for the pandemic.

Now going back to use the toolbox, I get a crash every time (report attached) saying "illegal instruction detected". I have seen a variety of these issues pop up in the best related to Mac's issues communicating with the dynamic libraries.

I believe some Security Update from Apple wrecked the compatibility with the mex file. I have not updated the OS or anything much at all. But looking at my software installation history there are 2 security updates total. One from before when the toolbox was still working (dated 3/4/20) and one mysteriously dated "3/31/76". So it's hard to tell which specific Secuirty Update it was.

However in collaboration with a colleague on his 2019 Macbook Pro we have tried:

1.) Running the code on R2015b, R2019b, R2020b [same error]

2.)Updating the OS to catalina and the latest and greatest patches [same error]

3.) Recompiling the mex files [same error]

The issue must be with MacOS becuase I verified the program is still working on our older Mac still running Sierra. For my system I am currently backing up and then going to restore a backup to a time I know the program was working. However, ideally I would like to figure out a solution that keeps functionaility in future OS's for the number of computers we have running this program.

Is anyone able to identify a workaround/fix that would get these mex files working on the newer versions of Mac's lovely updates?

I'm happy to provide any other information to help identify the problem.