Look at Configuration->File Types. Remove unnecessary, add your prefer types (overall 10). Move to top more frequently used or *.*

Some more words on what Ovg suggested already.

The Save As dialog in UltraEdit is an overloaded version of the common Save As dialog of Windows with some enhancements (options).

The common Save As dialog of Windows appends automatically the first file extension of the selected file type on save to the file name, except

1. the file name has already the file extension (not case-sensitive) as displayed (first) in the file type list on save,
2. the selected file type on save contains a file extension with a wildcard character in file extension like *.

So by moving list entry with *.* at Advanced - Configuration - File Types to top of the list, the automatic append of a file extension is turned off by default. When the user selects another file types list item before pressing button Save in the Save As dialog, the file extension of the file name is automatically replaced if one is already present by the (first) file extension of the selected file type, or the (first) file extension of the selected file type is appended to the currently displayed file name if there is currently no file extension.

This behavior occurs in all Windows applications using common Save As dialog of Windows.

What most applications do not support is a complete customization of the file types list used in Open and Save As dialogs.

UltraEdit for Windows v2024.1.0.32 uses indeed the first file extension in the syntax highlighting wordfile for a new file already syntax highlighted as default file extension on saving the new file with Save As. This is .php3 with the default syntax highlighting wordfile php.uew. If the user modifies the file extension to just .php in the Save As dialog before saving the file, UltraEdit appends the file extension .php3 because of .php is not in the list of file extensions as shown in Save as type. That is common Windows behavior.

One solution to get saved a new file syntax highlighted as PHP file by default with the file extension .php is modifying the syntax highlighting wordfile php.uew and add PHP as first file extension after File Extensions = in the first line of the wordfile. But please note that the default syntax highlighting wordfile html.uew has already the file extension PHP in the list of file extensions to apply the multi-language syntax highlighting of HTML + CSS + JS + PHP + … to all files with file extension .php. It is not good if two syntax highlighting wordfiles contain the same file extension as that makes it unclear for UltraEdit which syntax highlighting wordfile to use for a file with the file extension .php. The file extension PHP should be removed from the wordfile html.uew on having it added to the wordfile php.uew. That could result in getting a PHP file syntax highlighted only with php.uew which is no problem if the PHP files contain only PHP code and no HTML code or code in other languages.

Another solution without modification of any syntax highlighting wordfile is selecting in the Save As dialog window first All files, (*.*) for the option Save as type and then enter the file name with file extension .php. The file extension is kept as is now on saving the new file the first time which is already syntax highlighted as PHP file due to manual selection of this syntax highlighting language.

The best solution without modification of any syntax highlighting wordfile is using first the Save As dialog after creation of a new file and save the new file with file extension .php. That results also in an automatic selection of the multi-language syntax highlighting for HTML + CSS + JS + PHP + … and is for sure the recommended file handling behavior for new PHP files. This file handling behavior is also best if custom tab stop value and indent value or a special word-wrap handling or an auto-completion file are configured for files with file extension .php. In other words it is recommended to first save a new file with the appropriate file extension before beginning writing code or text to activate the right file extension based features of UltraEdit as configured for the used file extension.