Sudden memory leak?

I’m developing a project that only uses three objects. I started mysteriously getting massive memory leaks and CPU usage.

I changed all the pointer objects to shared pointers in case it was a destructor problem. It builds, but the leaks are still there.

I then commented out everything except the creation of these objects at the start. Still a problem.

If I let the program run, In Xcode’s Instruments it says that a leak is coming from ofSerial but I can’t tell anything further than that. ofSerial is being used to list Arduinos connected with a powered USB hub (working fine previously!) It still lists everything, but as soon as it’s initialised the CPU and memory both go nuts.

Any idea what might be causing this? Thanks for any insight!