Hi Janvee,
In my opinion you need to review Maximo logs to be able to find what is the root of this problem. You mentioned that this issue occurs only with a large number of work orders (WOs). It might be related to the settings of the maximo.mobile.fetch.timeout
properties in Maximo. However, in that case, you would likely receive a ConnectionTimedOut error instead of an Internal Server Error. Please review Maximo log file.