Magnification of view changing in Affinity Designer

[Furry]

I’m not sure if this is an Affinity Designer problem or a Mac problem. I am using an iMac running Mojave.

I have an object in Affinity Designer that I need to reproduce many times over. Using the Duplicate command under the Edit menu will not cut it because each new instance needs to be placed in a different position in my total design. So I am simply holding down the Option key as I click and drag to the new position. Mostly this is fine but, after three or four repeats, something weird happens.

Suddenly the magnification of my view changes as I click on an object to drag off a copy. If I am working at, say, 300% magnification, suddenly it will go to 245% as soon as I put my finger on the Option key. Sometimes it waits until I actually click before changing magnification. Sometimes it goes in the other direction and will change from, say, 245% up to, say, 287%. This zooming in and out could make one seasick! 

What is causing it? Is it a conflict of key commands between Affinity Designer and the OS? I didn’t know there was a key combination for adjusting magnification of view either in Affinity Designer or in MAc OS. And how do I fix it?

[h_d]

Just a thought: The default shortcut for the zoom key is Z, which is just above the left-hand option key. I wonder if you're either accidentally touching the Z key (if you use that option key) or if there's an issue with your keyboard. It might be worth disabling or changing the Z shortcut in preferences and seeing if it makes any difference.

(Not totally convinced this is the solution though.)

[Furry]

Thanks for the suggestion, h_d. But I suspect that is not the answer. I have discovered that using the Command key as a modifier rather than the Option key avoids the change in magnification and still allows me to clone the clicked object, though something else strange is going on there as sometimes it places the object selected in a frame with a line running from the centre of each side to the edge of the screen. I have no idea what that is about.

I have also discovered that holding down the Option key and sliding my finger up or down on the surface of the Magic Mouse (without clicking and dragging anything) changes the magnification up or down (or is it the other way around?) I think my initial thought about it being a conflict between something in Affinity Designer and something in the Mac OS is probably right. Perhaps, as I am about to click and drag I am (imperceptibly to me) nudging the surface of the Magic Mouse in an up or a down direction?

I look forward to hearing the views of others.

[Old Bruce]

25 minutes ago, Furry said:

the Magic Mouse

That is the source of your problem. There are OS preferences settings and Affiinity preferences settings which control how the zoom function will work with mice and scroll wheels in conjunction with modifier keys.

[R C-R]

6 hours ago, Furry said:

Perhaps, as I am about to click and drag I am (imperceptibly to me) nudging the surface of the Magic Mouse in an up or a down direction?

I find it almost impossible to use a Magic Mouse 2 with Affinity without accidentally doing tiny little nudges as my finger touches the surface as I start to click.

[Furry]

Hmmm... What can I say? Once again Old Bruce has put me right (with support from R C-R). Not that it was the answer I was hoping for.