modifier keys not working with remote screen sharing

When any modifier key (control/option/command/etc) is pressed on the controlling Mac (tried various machines), the iMac (running Sierra) that is being remotely controlled shows (in iMac's keyboard viewer) all the keys shadowed in above screenshot as if being pressed, and they do not go away when pressing other keys. Same result controlling the iMac from various other Macs that have El Capitan or Sierra. When clicking on a Finder folder, it opens in a separate window as if the Command key is being pressed (and it is not), meanwhile, the iMac's keyboard was disconnected on several occasions to test if it had anything to do with the actual keyboard, same with using various mice.

Using various keyboards and mice on either end did not make a difference in our trials. Working with Adobe InDesign is practically impossible; you cannot move items on same horizontal plane by holding down the shift key, you cannot zoom in/out by holding command key (or option key) while scrolling with mouse in any Adobe product (INDD, Acrobat, Illustrator). To type and switch the pointer to a cursor (even when the text tool is already selected) I constantly have to hit option+spacebar to temporarily be able to type, as soon as I go to a different text box or another paragraph the cursor turns back to the hand tool or pointer tool or magnifying tool randomly regardless of any actual tool being selected in INDD. Typing is also wonky (having to hit constantly Option+spacebar to be able to write) with Outlook, Word, and basically every app I need to do my job with. When using either machine locally, all functions and keys, mouse/shortcuts work perfectly. The issue is only when using screen sharing.

Apple is asleep at the wheel. This issue of not be able to function properly via Screenshare from Mac to Mac has stumped our IT department and unlucky for me they don't care, because they are replacing all Macs to PCs company wide across all our global locations. Apple support was of no help either, their solution was for me to bring the 27" iMac to an Apple location for a 'genius' to do clean install. Our IT department knows this issues affects all of our new and old Macs so since their is no official fix by Apple it looks like I can no longer use a Mac to work remotely when needed so I can't argue any longer why I can't just use a PC as our techs insist I do. Even our designers in London are now all on PC and that just is not right in my opinion because I feel Apple simply has decided to abandon their designer professional base that made them what they are today. And by the way, this bug impacts not only all Adobe products but all Microsoft products, like not being able to fill or copy cells and rows in Excel because it is like something seems to stick certain keys at certain times.

Since this issue does not impact Apple's bottom line from it's lucrative iPhone windfall, I'm afraid the outlook is gloomy for professionals that were counting on Apple to do the right thing.