Navigate to the BP_PlayerInventoryComponent and find the begin play node and add the shown below

b74da352889b60d31954ba56fb8d8607.png

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Navigate to the BP_MasterCharacter then to the begin play collapsed nodes, and remove the highlighted nodes shown below

0f4cdbe9bd694c1cf689551898a00f7a.png

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It should look like the image below after

5344d1c2aa2a58bf6e324837749248b5.png

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