Exiting a chip memory test leads to 0 kB of chip mem

[darrenfreeman]

I am using "DiagROM V1.3 BETA - 21-Feb-22".

Steps to reproduce:

1. boot into DiagROM
2. select 2, then 1, to test detected chip mem
3. push left mouse button to exit the test

Chip now reads as 0kB.

4. select 1, to test detected chip mem

Immediately get a spew of errors, with address line 10 showing an error.

[screwtop]

I can't add more detail but I have seen this as well, DiagROM 1.3 on an A1200.