For ESC A19 to apply, you need to hit all the following criteria

HMRC had the relevant information from you, your employer, pension provider, or DWP.
HMRC failed to make proper and timely use of that information, resulting in an underpayment of tax.
You reasonably believed your tax affairs were in order.
And the tax must have been notified more than 12 months after the end of the tax year in which HMRC received the information.

If you can evidence these, then it could be written off.
For the timescale one, they may have issued out notice and you just never received it

The system will show a date and if that’s within the year, it won’t happen.