At cosmos-sdk v0.36.0, many breaking changes were introduced, regards to the HTTP response format.
cosmos/cosmos-sdk#4536
cosmos/cosmos-sdk#4837
https://github.com/cosmos/cosmos-sdk/blob/master/CHANGELOG.md#breaking-changes
To use the panacea-core v1.3.1 which uses the new cosmos-sdk, this Javascript SDK must be upgraded.
Related to medibloc/panacea-java#8