Hi @dymayday
Inter-canister query calls are not supported currently. There is an ongoing discussion here: Inter-Canister Query Calls (Community Consideration) - #53 by ulan
Until the discussion is resolved, the best workaround is to move the query calling logic to the client side, so that the browser performs both queries to A and B.
Looks like dfx unintentionally enables the (incomplete) prototype implementation of inter-canister query calls. (The technical reason is that the prototype is enabled for system subnets and dfx uses a system subnet configuration). The SDK team is working on switching dfx from the system subnet config to the application subnet config with many additional benefits like proper cycle accounting. Once the work is complete, the discrepancy that you’ve discovered will be fixed.
IIUC, the title of the post about losing access to canister doesn’t seem related to the contents. Did you mean to use a different title here?