Work permit reject

What do you mean by "merit issue"?

And what is "quit quietly"?

If you terminated your previous employment contract properly, obeyed the contractual notice periods and/or paid the agreed penalty, then the rejections have nothing to do with your previous job.

But if you broke the contract, then this could be the result.

before this everytime my work permit reject company just told me no reason. but last month i got another offer, and my work permit got reject due this reason “Mom assesses each work pass application  on its own merits taking into account various factor”. 3 years ago i stop my work at this company without any notice and go back to malaysia due pandemic. what should i do if i want to work in singapore again?

So you broke the contract by just disappearing without informing the employer?

In that case, the employer probably (and rightfully) lodged a complaint against you with MoM.

Then you should contact MoM and ask how long the ban will last and whether there is anything you can do to lift it earlier.