Suddenly unable to move many start menu icons, icon folders

[HansHP]

This happened suddenly overnight without apparent reason. I have a lot of icons on my Lumia 735 Start menu and many icon folders arranged by topic like Finance, Interests, Travel, etc., containing relevant icon links. I never had problems moving or rearranging them by pressing and holding then moving. Now, for icons starting about half way down the Start menu, when I press and hold to move an icon or icon folder I am transferred from the Start page to another open program page, e.g., this forum page, even though I had no intention to end up there. If there is no other open page, a msg " loading" with moving dots appears and I am transferred to a blank page and then back to the Start page. Hence, I am unable to rearrange my Start Page icons except in the top half of it. Tried turning phone off/on and soft reset without success. Hesitant to try changing page layout (icon size from Personalization) since that's a lot of work to reformat my Start Page layout. Also want to use hard reset only as a last resort. Only thing I can think of is that the phone can only handle that many icons and folders and then has a problem. Found nothing on this topic on the web. Any ideas?