Double click doesn't open txt files

[ObiwanKennedy]

Hello,

Some months ago, I upgraded my 8.x Textpad version to the 9.0.1 version.
I noticed that a double click on a .txt file didn't launch or switch to textpad.exe. Somewhat boring !
Now, with the latest 9.3 version, the same problem remains.
Relevant Windows 10 associations were checked and unset (switched to Notepad) and reset and checked again, and TextPad is configured to replace Notepad. Nothing works.

The behaviour is the following : when I double click a txt file in explorer (or when I use the Send To context menu), it switches to my already opened Textpad app, but the file is not opened.
Even if I double click several times on the same file (I have seen forum entries where it is said the it didn't work only on the first double click).

Now, the only way to open a .txt file with Textpad 9, is to use the File/Open menu.

If anybody has a fix, I would be very glad.
Thanks in advance.

O.K.