I'm being asked for installment tax payments, though I'm a salaried employee. How do I make the notices stop?

I’m in Canada.

For the past several years, I worked as a freelance contractor. Since January, I have held a full-time position.

I’m certain that I don’t owe any income tax. My pay is subject to hefty deductions, such that next spring I should be able to get a refund.

Unsurprisingly, I have received notices from the CRA asking for installment payments. It makes sense that if someone had been self-employed and paying by installments, they will likely continue to do so, and are based on projected income. Even if I were completely unemployed, they would still be coming.

The notices, however, make no mention of any year-to-date remittances. They seem to be insinuating that I have not paid any taxes for this year whatsoever. I seem to recall that in the past, these notices would reflect year-to-date remittances, and ask for the projected remaining balance. If I log into my CRA account, I also don’t see any activity there, so that is consistent with the notices.

Could it be that my employer isn’t actually sending money to the CRA? Or is it normal for that type of transaction not to show up in the individual’s CRA account?

Is there some process for laying this matter to rest so the notices stop and I don’t get surprised by some sort of penalty or interest payment down the road?

I suspect things are probably fine and I don’t have to take any action, but that’s just a hunch not based on any official confirmation or factual evidence.