On the Info screen in Profile, try answering "yes" to "Last name changed in 2022?" (right under where the Last name shows).  See if that then lets you e-file.  I suspect that answering Yes to that question will change some internal e-file binary code from 1 to 2, or from 0 to 2.  I cannot locate the code myself - let me know if that works.

If CRA's records are different, it would not be from the T4.  That does not establish the CRA name field.  They may ask for support, such as the birth certificate when they get back to work and start reviewing tax returns.