Only po file get save and .mo file never updated

I did use loco translate previously on another site and it worked well. I believe in order to see the translation successfully on the front end, both po and mo file need to be updated and compiled. However, the website I am currently working on, only po file get saved the modification and mo file never gets updated nor compiled. I have tried a couple of times, disabling plugins but still it doesn’t work. Is this a known issue or me doing something wrong ? Thanks.