Solution: Could you please check if Catalog Price Scope config is Store view? (Configuration -> Catalog -> Catalog -> Price ->Catalog Price Scope )

http://prntscr.com/m0ups8

FYI, it's the configuration to enable our extension on Backend. Thus, if you keep Catalog Price Scope config as Website or Global, it means that our extension is enabled in code but not on Backend, the issue will appear. 


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