Notepad: Inserting Symbols work on one computer but not another

I have two identical laptops running the same Win10 version and configured identical. The files are mutually synced via OneDrive.

I have always been able to insert and display logic symbols into Notepad UTF-8 files. But today files on one laptop lost some symbols (were replaced by square symbols) and when I tried to reinsert them I got " instead of the symbol.

The other computer is fine. And when I take the messed file to it, it displays correctly!!!

This is weird and does not make sense

Is there any setting that could affect symbols in Notepad that I am unaware of and got messed up in some way? Any other ideas?

bro67 said:

Wingdings will show up if you do not have those fonts installed.

I don't see how this would be the reason.

1st, the same fonts are installed on both computers. 2nd, this happened on one computer but not the other, without the fonts being touched.

Let me try again: Everything was fine on both computers. Without me changing anything, one computer developed the problem.
So my question is what could have caused this and what can I do to restore the computer to its previous state in which this was working.

I don't understand what "make sure you are not making changes with a Microsoft Live account." mean. I am unaware that I made any such changes.

Pls read more carefully. What I said was that it "HAS BEEN working fine", then it stopped and I DID NOT MAKE ANY CHANGES.

Had I made any changes I wouldn't have come here to ask because I would have known what caused it. I ask because it stopped working without me making any change.

Can you tell me what/were I need to check what you are suggesting?

AFAICT fonts and language settings are the same on both computers.

Let me retry to explain the problem:

I had a .txt file saved as UTF-8 containing logic symbols. It displayed correctly in Notepad on two identical laptops that are identically configured in Windows 10.

Suddenly one of the laptops fails to display the symbols without any changes made to it or the computer -- it displays squares instead. When I try to re-paste the symbols into it, it inserts quotes instead. Even when I use a USB drive to transfer the file from the laptop that displays it correctly to the one that does not, the problem persists.

I am guessing that there is some setting on the laptop that got messed up somehow and must be fixed, but I have no idea what. Anybody has any ideas?

I am familiar with that program, but setting the systems to default is not a solution to the problem.

Both systems are extensively customized and there is no way I am going to redo all that. But they are BOTH customized identically, so they should both behave the same way. Furthermore, they are both cleaned of MS bloat, spying and OS features that consume resources but do not serve any needs (e.g., Edge, Cortana). Chances are resetting to default will bring them back.

I need somebody who is knowledgeable about the system details of Notepad workings with symbols who knows of some setting that could cause this discrepancy and how it could be fixed, not reverting the systems to default.

2nd, they are both cleaned