Compatibility Issue with Multi Page Chest

[delprince979]

Minecraft Version: 1.12.2
Inventory Tweaks Version: Inventory Tweaks 1.63

Sorting in a Multi-Page chest (from the Multi Page Chest mod) it doesn't work as it should. It moves everything to the beginning, but doesn't actually sort them at all. For example, let's say in the chest the only things in it are 30 nether quartz, 64 iron ingots, then a blank spot, then 64 nether quartz again (items not specific, this is just for the example). Then, if I press the sort button, it just kinda shifts everything to the beginning, but still in place: the result would be 64 nether quartz, then the 64 iron ingots, then 30 nether quartz. It doesn't bunch the two stacks of nether quartz up like it should.

I'm assuming the problem is something to do with the unique multi-page aspect of the chest, although I can't guess much past that. Please note also: I'm aware of the disclaimer on the main page. The Multi Page Chest DOES show up with the button, and so I'd assume that the mod IS sending the necessary information, and it seems like this mod might just not be handling it correctly because of the unique format. I am not a mod creator/editor so I don't know though, I'm just saying that I HAVE read the disclaimer and believe this might be a different issue. Tell me if I'm wrong though, I'm not pretending to know anything that I don't.

Is there any way to fix this? And please, if I should be reporting this bug to the author of the Multi Page Chest mod instead of here, let me know politely - I just don't wanna be shoving issue reports left and right without knowing where they should go first, so I'm starting here.

Thank you so much in advance though, and great job on the awesome mod!