Image resize script worked on some photos but not others

If you follow JJMack's advice and re-record the canvas size step to contain both width and height entries all should be fine.

As an exercise, I hacked the following scripts together (not to be confused with actions)...

Resize image canvas to 2500px square with white bg.jsx (suitable for recording into an action for batch processing)

/*
Resize image canvas to 2500px square with white bg.jsx

https://community.adobe.com/t5/photoshop/image-resize-script-worked-on-some-photos-but-not-others/td-p/11572554

https://community.adobe.com/t5/photoshop/canvas-resize-to-square-for-a-large-number-of-images-using-script-e-g-image-is-currently-1020-x-600/td-p/6148635
https://coffeeshopped.com/2008/11/conditional-image-resizing-with-photoshop-and-javascript
*/

#target photoshop

// Save the current ruler units
var savedRuler = app.preferences.rulerUnits;

// Save the current background color picker values
var savedBackgroundColor = app.backgroundColor;

// Set ruler units to pixels
app.preferences.rulerUnits = Units.PIXELS;

// Set the background color to white
var bgCol = new SolidColor();
bgCol.rgb.red = 255;
bgCol.rgb.green = 255;
bgCol.rgb.blue = 255;
app.backgroundColor = bgCol;

// Set the active document
var doc = app.activeDocument;

// Set the target size in px
var targetWidth = 2500;
var targetHeight = 2500;

// Resize if height > width (portrait-mode) resize based on height.  otherwise, resize based on width (landscape-mode)
if (doc.height > doc.width) {
    doc.resizeImage(null, targetHeight, null, ResampleMethod.BICUBIC);
} else {
    doc.resizeImage(targetWidth, null, null, ResampleMethod.BICUBIC);
}

// Resize canvas to longest edge
doc.resizeCanvas(Math.max(doc.width, doc.height), Math.max(doc.width, doc.height));

// Restore the ruler units
app.preferences.rulerUnits = savedRuler;

// Restore the saved background color picker values
app.backgroundColor = savedBackgroundColor;

Resize image canvas to square with white bg via prompt.jsx (suitable for manual use for variable resizing)

/*
Resize image canvas to square with white bg via prompt.jsx

https://community.adobe.com/t5/photoshop/image-resize-script-worked-on-some-photos-but-not-others/td-p/11572554

https://community.adobe.com/t5/photoshop/canvas-resize-to-square-for-a-large-number-of-images-using-script-e-g-image-is-currently-1020-x-600/td-p/6148635
https://coffeeshopped.com/2008/11/conditional-image-resizing-with-photoshop-and-javascript
https://gist.github.com/MarshySwamp/3770f9f201814669fa33e7c72b31a47f
*/

#target photoshop

    (function () {

        // Save the current ruler units
        var savedRuler = app.preferences.rulerUnits;

        // Save the current background color picker values
        var savedBackgroundColor = app.backgroundColor;

        // Loop the input prompt until a number is entered
        var origInput;
        while (isNaN(origInput = prompt("Enter the square size in pixels:", "2500")));
        // Test if cancel returns null, then terminate the script
        if (origInput === null) {
            alert('Script cancelled!');
            return
        }
        // Test if an empty string is returned, then terminate the script 
        if (origInput === "") {
            alert('A value was not entered, script cancelled!');
            return
        }
        // Convert decimal input to integer
        var inputToInteger = parseInt(origInput);

        // Set ruler units to pixels
        app.preferences.rulerUnits = Units.PIXELS;

        // Set the background color to white
        var bgCol = new SolidColor();
        bgCol.rgb.red = 255;
        bgCol.rgb.green = 255;
        bgCol.rgb.blue = 255;
        app.backgroundColor = bgCol;

        // Set the active document
        var doc = app.activeDocument;

        // Resize if height > width (portrait-mode) resize based on height.  otherwise, resize based on width (landscape-mode)
        if (doc.height > doc.width) {
            doc.resizeImage(null, inputToInteger, null, ResampleMethod.BICUBIC);
        } else {
            doc.resizeImage(inputToInteger, null, null, ResampleMethod.BICUBIC);
        }

        // Resize canvas to longest edge
        doc.resizeCanvas(Math.max(doc.width, doc.height), Math.max(doc.width, doc.height));

        // Restore the ruler units
        app.preferences.rulerUnits = savedRuler;

        // Restore the saved background color picker values
        app.backgroundColor = savedBackgroundColor;

    })();

Here is the script:

It worked on most of the images, about 100 of them, with this as the final result:

It did NOT execute for about 30 of them. I ran the script again on just the 30 that were left and still same result leaving the images as is in their various dimensions: 

Nobody can help you unless we know which exactly script/action you are running and what is inside script/action. 

"but the other 25% of them it didn't do anything"

Do you mean action/script failed to execute steps or something else? We need more info and most likely action or script to examine.

If its a script post the script. If its an Action Expand the action and all the steps in the action in the actions palette and post a screen capture