I too, lost one of those things a few years back, and paid the ridiculous price to replace it. And yes, it doesn't hold itself in place very well, and is guaranteed to go missing again in the future if you don't use something to keep it in place.
I found a gooy, sticky, rubbery tape, much like the stuff that is used in mailers, to hold things in place. Credit cards come to mind, but Northern Tool uses something similar to hold their $5, $10, etc. discount cards in place on their mailers. That is the perfect material for holding those plastic parts to the screw head that is behind the piece you replaced.
Mine has worked for 4+ years now. It can be removed and stuck back in place a few times before needing to be renewed with fresh stuff. I can't remember the name or brand. It is sold in a roll of "tape" stuck between 2 pieces of release paper. You just wad up a little ball of it, kinda like "buggers", and stick it in there. Great stuff. I think it was in the Walmart sewing or crafts area of the store. But here is a link to similar stuff that is way more expensive than the version I bought.
Find something, or you'll be buying those pieces again. Double sided 3M mounting tape might also work, but is way more sticky than the material I reference.
https://www.vat19.com/item/joes-sticky- ... itive-tape