Extend surface by negative value not working on simple surface R7(SR13)

Simple planar 1 degree square surface. When I run the ExtendSrf command and type in “-10” + Enter (after selecting an edge) nothing happens. I can click and drag the edge in a negative direction but cannot enter an exact value via the command line. R6 (SR35) works as I expect it to.

Screen capture links and 3dm file below:

R7 ExtendSrf - Capture

R6 ExtendSrf - Capture

2022-01-11 ExtendSrf Negative.3dm (2.6 MB)

Hi Paul - I see that. thanks.
RH-66949 ExtendSrf: negative values fail