Your international adviser is right. The law is that u can travel out of US and come back while ur OPT application is pending. If ur OPT is approved and u went out of the country without getting job, then ur OPT will be terminated.

So as per law its safe to go while OPT is pending. But u never know  when u r returning particularly in these ongoing conditions. People having job n going for H1 stamping have been stuck there for couple of months.

So as per law it is allowed to enter. But u should take ur own risk. It all depends on the person at port of entry during returning. I would suggest going only after having job offer.