I found this bug recently after playing in the 1.19.40 version. So, in creative, when you select a block, you can either put it in your hotbar or put in in your inventory. However, after the update, the inventory seems to refresh for every button I press. So, when you want to take a item from the creative inventory into your personal inventory, you are unable to do that as that item is instantly deselected (a). This goes vice versa, when you select an item to delete from your inventory into the creative menu, that item is instantly deselected (b). Moreover, the items in your hotbar will not be able to be deleted just by selecting it and tapping on any part of the search menu. Instead, you have to select that item and then click on an item in the Creative Menu to actually delete it (c). Some UI packs have an option to have a button as a substitue of shift-clicking on desktop to instantly get an item to your hotbar or put an item from your hotbar to your inventory (d). It used to be much more easier before compared to now.

A step-by-step version to reproduce it would be as follows:
To reproduce (a)
1. Create a Creative World in 1.19.40
2. Select your inventory
3. Click on any block/item in your Creative Menu in any section
4. Click on one of the cells to put that item in your inventory
Expected: The item would be in your inventory
Outcome: The item would not appear in the inventory

To reproduce (b)
1. Do the same as for (a), but stop at 3 and put the item in your hotbar instead
2. Transfer the item to your inventory
3. Select the block
4. Go to any section of the Creative Menu (easier in search section with only one item showing)
5. Click on a empty space / blank space
Expected: The item would disappear from your inventory
Outcome: The item stays in your inventory

To reproduce (c)
1. Do the same as for (a), but stop at 3 and put the item in your hotbar instead
2. Open the Inventory Screen
3. Select the object in your hotbar
4. Click any other Creative Menu section
Expected: The item remains selected
Outcome: The item is deselcted

To reproduce (d)
1. Enable a resource pack that gives you the option (I used the [Ty-El UI pack|mcpedl.com/the-ty-els-ui-pack/] from MCPEDL
2. Enter any world with Pocket UI and open your inventory
3. Click on the button in the top right that has the picture of a finger to make it turn to 'Auto Mode'
4. Click on anything in your hotbar to put in your inventory
Expected: The item is moved to your inventory like you just shift-clicked
Outcome: It stays there in the same hotbar slot
The pack creator said that it was the problem of the new update and not his code

It would be nice if these bugs were fixed. Thanks.