Why is my shared matlab engine not accessible after few days?

I share matlab engine from the command window to let other application connect and do something. I share it by writing

>> matlab.engine.shareEngine

in matlab command window and I check shared engine name by typing

>> matlab.engine.engineName

. Good thing is i'm able to find the session and can communicate with matlab from external application.

However, problem is if I don't close my matlab for 1-2 days and keep engine shared but not used by any application. So after 1 or 2 days I try to connect to shared matlab engine from external application, but i get error. Then I tried debugging in matlab to see shared engine name and this is what I have observed.

>> matlab.engine.shareEngine
Error using matlab.engine.shareEngine
The courrent MATLAB session is shared already.

>> matlab.engine.engineName
ans = 

0x0 empty char array

Matlab version - R2018b

Thank you,

Pritesh Gohil