Updated image for Sprite shows once and reverts to former image

Sprite is located in Canvas.
Under Sprite Properties, I uploaded another .png image to replace current image. I even removed previous .png image but it still shows up.
New uploaded image does not act right - shows once and then old image appears or new uploaded image does not show up at all.
In preview in Media Column, image previews fine.
What did I do wrong? Both images are .png

In many browsers, F5 refreshes the screen.
Try that.

If this is happening at run time, read the blocks to see where the picture is changed.

I didn't change picture in blocks.
I used Sprite Properties and uploaded new picture there. I thought picture would upload under Sprite name and would still work with "Sprite" in blocks since preview in Media shows new image.
When do I press F5, after I upload image or in the blocks area?

I thought when I uploaded a new image under properties, the new image would automatically take over and the old image would be gone.
Is there a tutorial on image specs for mit app inventor? I copied image from google, put it in paint and resized image by pixels. Then I uploaded saved picture from my computer to Media in mit app inventor.
Is there another way I am suppose to do this?

Try restarting companion / browser

that hasn't worked so far.
But I just saw an article that says: For example, if you have an image asset named kitty.png , you can use it as an image: just set the Picture property of an image component to the text kitty.png .
Can you show me this in blocks?

Working OK here