T4 box 20 in error?

Wondering if anyone has ever encountered something similar - I have client who’s T4 for 2025 doesn’t show an amount in box 20 as it previously has (flagged for review by TC). A bit of digging suggests that there may never have been a pension plan, just a group RSP which we have been deducting per receipts…the only change my client is aware of is that as of 2025 the payroll is now being done by ADP. Not sure if it’s wise to stir anything up, thoughts?