I just got a CR70 last night, and was testing it out on a 5AXP4 I also received last night. Except for some confusion with the book settings vs. Universal Adapter settings, it tested fine.

However, I found that the Emission test result is dependent on the setting of the CUTOFF control. If it is turned all the way down the result is poor, and if turned all the way up the result is very good. The operating manual intimates that the EMISSION test automatically sets both grids to the conditions to perform the test. Certainly the manual makes no note about the cutoff setting having to be set to perform the EMISSION test.

Might there be an issue with my CR70?

With the function set to cutoff, position the cutoff control so the meter needle is inside the black "cutoff" box. Then do the emission test.