As far as documents go, I have seen this happen with OpenOffice Writer, as well as when copy pasting stuff within a browser environment to a form. It would be easy to pin it to just one culprit if it was just one program or application that has this issue.
One of the most critical of mishaps was when I had a long password stored from earlier when copy pasting it from a notepad text document that holds passwords for websites in which I didnt want to type the complex alphanumeric with special character password and I was going to share with a friend on facebook an easter egg within a video game we were playing that I had a screenshot of, but didnt want to send the whole screenshot but just the item of interest as I selected a smaller section of an image that I opened in mspaint, selected to copy this via the right-click copy. Then went to facebook to right-click and paste and it wanted to drop my long password from being used earlier. I tried this over again and same results 3 times, I then decided to use CTRL + V and it sent the image instead of the password to facebook messenger window.
I had sort of ignored it until most recent when a password almost went broadcasted out onto facebook because the buffer is doing this oddity.
Maybe I just need to avoid the right-click of copy/paste and force myself to using the hot key combinations for CTRL + C and CTRL + V ... but I dont quite get why there is a difference between using your mouse to copy/paste or using keystrokes to copy/paste. I thought its the same function, but this weirdness is pointed out that there are differences in whats called from a buffer of stacked items where you can have text and an image there at the same time and if you right-click and paste your getting old text from earlier and if you use CTRL +V your able to get the latest image to paste.
Windows 10 is the only system that does this. I dont have any special clipboard or screen capture programs installed, its a pretty bare bone install of 10 with just Steam added to it so that I can play my games on it. All other computers that I own that are Windows 7 or another OS other than 10 dont have where the buffer acts like 2 separate buffers. I've never seen a recall ability in a buffer before other than at command prompt you have use arrow keys to bring back a list of what was entered earlier but that has nothing to do with the buffer for copy/pasting. The minute print screen is used or copy is used on all other systems I have it wipes out that buffer space and places the newly captured information either a screenshot or text and when using either hot keys or right-click for copy/paste your getting the newest information pasted and not something from earlier.
I am going to mess around with this more tonight when I get out of work to see if I can discover anything else about this that points out why its acting this way.
Lastly the browser in use is Edge.. just in case that rings a bell for some feature in edge that I am not aware of as the interaction of the copy pasting is mainly from the web to local document or from local document to the web, BUT I have also seen this happen when working between two local environments where an area of an image was selected as cropped and right-click copy and then open the Open Office Writer document and right-click paste and its dumping text information from earlier instead of the latest image selection copied. However if I avoid the right-click copy/paste or right-click to copy but complete the pasting process using CTRL + V it will paste the content correctly that I want.
So I know how to get what I want pasted by using CTRL + V instead of Right-Click Paste, but its annoying that the mouse controlled Copy/Paste and Hot Key function to do the same thing should be doing the same thing I would think and it isnt.