To reproduce:
1) Login in the MyOSCAR portal as a demograhipc user
2) Click on the 'Immunisation' link to access the immunisation page.
3) If an immunisation record does not exist, create one (fill in all fields; dose)
4) If the record exists, click the PENCIL icon to the right of the record (edit)
You will notice that the 'dose' is not retained and doesn't populate the field
*** note ***
I wasn't able to find anywhere in the docs that determined this to be as designed
https://source.oscartools.org:8080/#change,5785