Every item, question and answer has to have an unique Link Id and code that makes sense(look for asterisk for required in builder).
Everything done for skip logic and answer lookups require a link path starting from group down.
Take a look at the FHIR spec example or pull in a similar form like this one.
USSG-Family-Health-Portrait.json (111.9 KB)
Reporting works fine if form is designed correctly. Remember to look on the Link Id as paths to the item starting at say the group o g1 then first question would be g1/q1 etc.
Also I think current lforms version has a rendering bug for these type forms. Your form would still break regrdless until link ids are fix. Note how many times I’ve stressed the link ids!
Once I verify, I’ll put up patch as a new lform release has come out.