Change from ISO-8859-1 to UTF-16

With the latest mp3tag that I installed, it seems that any operation done through the software to modify or enrich the tags of my mp3 files automatically results in a modification of the encoding choice, from ISO-8859-1 to UTF-16.

However, I have almost ten thousand mp3s, which work perfectly well in ISO-8859-1, both on my various PC software and those on my multiple Android devices.
I therefore do not want this character table transformation each time I interact with the tags of my files.
So is there a simple way to prevent this with the latest version of your excellent software?
(In passing, I noted that this table transformation did not occur with earlier versions of your software, for example v2.82)

Thanking you in advance for your response

See Options Ctrl-O > Tags>Mpeg
for settings to write ID3V2 tags.

Please note that ID3V2.3 in UTF-16 offers much better support for non-ascii characters than the ISO-8859-1 which relies on your system's code page to display the correct characters.

So, actually, I would go the other way and transform all ISO tags into UTF tags.

Thank you for your prompt response.
It's working properly again, and I must admit I searched for a long time on this problem, without success... before deciding to write to you!

Transforming all ISO Tags into UTF seems to me to be a good initiative:
For your information, my CD to Mp3 conversion chain uses CDex and PSPad Editor, before finalization with Mp3tag.
And if Mp3tag sees my texts in ISO-8859-1 form, yet PSPad provided them in UTF-8 form...

Too complicated for me!
Thanks again

See also here:

So, in fact, it is more likely that older programs and devices have problems with UTF-16.
UTF-8 is used for ID3V2.4 which is probably even more recent than ID3V2.3 and UTF-16.

To transform the tag encoding
Set the options to write UTF-16 tags.
load the files
select the files
press Ctrl-S to save the tags again.