Selecting text doesn't work reliably

I've noticed the following problems:

1. The action bar above the keyboard sometimes obstructs the cursor when editing a line in a note in the bottom half of the screen:

2. When long-pressing on a word to select it, the selection magnifying glass often appears to be stuck for a few seconds before the cursor finds the correct position.

This behavior is especially pronounced when long-pressing on bullet points.

3. Also, in a few cases, the cursor doesn't find its intended position when long-pressing. For example, sometimes the magnifying glass pops up at the last cursor position or disappears entirely instead of appearing at the position of the long-press.

4. When trying to select an entire line in a note, swiping from right to left from the middle of a line to the left edge of the screen causes the selection to disappear.

This text selection behavior doesn't occur in the Apple Notes app for comparison.

iOS Version: 3.1.6