I looked up the specs on the named devices, and the Tab 2 has either Bluetooth 3.0 or 4.0 depending on which version, whereas the Honor 5C has 4.1 and the S7 has 4.2, so it shouldn't be a Bluetooth limitation (as the versions before and after the version Honor 5C uses aren't problematic.)
Check to make sure the Honor 5C isn't connecting to anything else over bluetooth (headsets or whatever) to eliminate interference as a cause. Maybe check for firmware updates on the Honor 5C?