One cell at the right end of the screen is ignored

One cell at the right end of the screen is ignored by ConPTY (18317). (17763) does not.
I tried it with ConPTY sandwiched by Vim, but it does not look like this in winpty.
It uses VMware12.
It seems that backspace is shifted to the left by one cell when you hit repeatedly across lines.

I felt like Vim's problem. I will review the code as well.

When erasing the character at the right end of the screen, a blank character is output at the right end of the screen, but it seems that there is not enough sequence (0x0D 0x0A) to bring the cursor to the next line.

Therefore, the cursor does not reach the cell at the right end of the screen in the immediately following sequence (\b).

[zadjii-msft]

Okay, so to make this clear, his is something that's regressed since RS5 (17763).
Looks like even in wsl interop this repros. I've filed MSFT:20266233 to make sure this gets fixed.

[DHowett-MSFT]

Hey, I forgot to tag this one! It's fixed as of insider build 18834.