>>If you have multiple Bluetooth devices in close proximity, interference is possible. I haven't encountered any cases like that myself.
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>The same USB does for both, the keyboard and the mouse. So, as far as the keyboard goes, it wouldn't be a factor. Around here, I do not see any other devices for wireless other than the wireless router for my Internet. Maybe that is the case.
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>>Dying batteries in the mouse can cause behaviour like that.
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>This one is on a rechargeable device. I wonder if there is anything in there that need to be changed.
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>>With the mouse cursor jumping around, another common problem is a bad mouse pad. Types that cause problems with optical mice:
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>I am not using a pad. However, I put something under for a while, with solid color, such as black, and after a while, it started to do the same thing. Yes, on top of glass, it is terrible. When I go downstairs, and put the mouse over the glass, it is not working at all. I have to put something under. However, as surprisingly as it gets, going under, which is about 50 feet away, make it work ok.
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>>If you have a plain wooden desk surface (either solid or veneer), that's an excellent optical mouse surface. Try that to see if your problem persists.
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>The one I have presently is like an arboright materiel with patterns. So, I figured at first it was the problem. So, that is why I put a black binder to try it on. I thought I found the reason but after a while, it started to do the same thing. IAC, a new surface will be put on top of the desk to replace the actual one. That one will be black solid all over.

If it's a regular, repeating geometric pattern on the scale of your average mouse motions, that's one of the problem surfaces. Also solid colour (especially black) is not good either.

Maybe you could get a mousepad with a fake wood grain or autumn leaves pattern - something non-repeating with lots of features for the mouse sensor to track.

The mouse pad I use is excellent - a slightly rough plastic surface embedded with thousands of randomly scattered metal flakes.

One last thing to check is that there is not a small piece of lint stuck in the laser sensor - that can make the cursor jump around, too.