Error expanding variable containing a directory name

[Lutz Adam]

Configuration Information [Automatically generated, do not change]:
Machine: x86_64
OS: linux-gnu
Compiler: gcc
Compilation CFLAGS: -g -O2 
-fdebug-prefix-map=/build/bash-a6qmCk/bash-5.0=. 
-fstack-protector-strong -Wformat -Werror=format-
uname output: Linux fractal 5.4.0-42-generic #46-Ubuntu SMP Fri Jul 10 
00:24:02 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
Machine Type: x86_64-pc-linux-gnu

Bash Version: 5.0
Patch Level: 17
Release Status: release

Description:
       The content of $ML is "/media/lad".  There's a directory 
/media/lad/p24. Typing the command
            ls $ML/p24<TAB-key>
       a backslash is put befor "$" and the line looks like:
            ls \$ML/p24/
       Typing the ENTER key shows:
            ls: cannot access '$ML/p24/': No such file or directory.

Repeat-By:
        Create a variable containing a directory name. Put a 
subdirectory there under.
        Type a "$" and the variable followed by a slash, the name of 
the subdirectora and the TAB-key.


The OS is Linux Mint 20