The cursor issue [when using the End key]

I have tried using “end” to move to the rightmost part of a sentence, but the cursor moves to the rightmost part of the display, not the rightmost part of the sentence. The space between the end of the written sentence and the position of the cursor is similar to the space created by “Tab” or “Spacebar”. However, the space cannot be dragged, and the moved cursor is not moved by the arrow keys, backspace, etc. As a result, I cannot use the “end” key when writing a document. How can I solve this problem?

Edit / Select / Select sentence (as a shortcut) followed by the right arrow. (?)

You could also use a RegEx to look for the next uppercase letter, but I don’t see that being convenient.