I have the exact same problem. This is what I tried.
In the T4RIF form I keyed in unlocked amount under the box titled "- portion of Box 16 transferred to a RRSP/PRPP (click the ?)"
After that, the two slips did indeed "cancel" each other.
See the snip below where the unlocked amount is $50,000.00
I would appreciate it if an expert chimed in and confirmed that what I tried is correct.