I am assuming that the attributes that I am inserting are not really 'input' attributes, and the MDT byte is not behaving as normal. This is what has me stumped. Why is the MDT byte not being set when I modify the field?
You cannot expect BMS to map properly a messed up screen, because that's just what You did
did You read the 3270 programming guide on how the fileds are defined for proper 3270 handling ? looks like not
BMS tries to map things according to the map definition, not according to Your messed up screen
BMS in mapping fields is not driven by the attributes, but by the SBA and START FIELD commands ,
review the design
You might get away with messing around with output fields, when doing it with INPUT fields the best You can expect are unexpected results
misplaced, misMapped fields at least, but on the long run BMS MAPPING errors
if You need Dynamic input fields You will have to <parse> yourself the unformatted buffer read.