Hi,
if you post a HU goods receipt the stock will be posted on a specific bin. The system needs to know which bin this should be. Usually you can let this bin be determined or enter it. This information is stored on the delivery item (for TUs it is slightly different).
If you now have a situation where you have multiple items and you have different goods movement bins entered/determined, then which bin should be used for the goods receipt (due to physics it can only be on either the one or the other).
Therefore check how you fill or determine the goods movement bin.
Best regards
Markus