Something a bit strange with graphics these days... Unable to get line/arrow horizontal

[cos]

I'm getting a little exasperated with Word 365 in particular with the graphics.




I have an arrow graphic drawn on a page (table grid lines added for visibility).



When I click on the right snap point to make the arrow horizontal, it snaps to just above the horizontal and I cannot get anything in between:



I have 'Snap object to other objects' turned off.


What other objects are there to control this?


Another issue is when I use the arrow keys to move the arrow. If I press the down arrow it moves slightly down and to the right. If I keep pressing the down arrow, it keeps moving down and right but after a few presses it suddenly jumps a few spaces and continues down and right. This then repeats after another few presses.


The same also happens when I press up too.


Does anyone have any ideas what is going on here?


Thanks