Steps to reproduce
On mobile, enter multi-select mode. Click around on different items to select/deselect them.
The items become highlighted (selected) or un-highlighted (deselected) as you press them.
Most of the time it behaves as expected, but occasionally (~15% of the time) when selecting an item it will open the keyboard with the cursor at the beginning of the item and clear out all of your other selected items.
I noticed this when selecting some items in my grocery list, and after selecting ~10 items the keyboard popped up and cleared all of the selections and I had to start over again. For bulk actions on many items this bug makes it really hard to use the feature.
Can eventually repro 100% of the times I try it.
See this screen capture: https://streamable.com/95csej
Android 10 Chrome browser.