When you place 2 slabs on top of eachother to make a full block, it is impossible to place water on the side of the block. This might be due to the game trying to fill the full block with water because it's still 2 slabs.
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[Mod] Neko
migrated
Thank you for your report!
However, this issue has been closed as a Duplicate of MC-126906.
It has been linked to this report. If you have additional information, please add it to the duplicated report.
Please search before reporting, as it's likely that one exists already.
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