How to fix missing wishlist icons in Google Play Store?

I have noticed that some of the time, the Add to Wishlist icon is missing from some apps within the Google Play Store.

Some apps show the icon, some don't. Grabbing a different device shows the same issue: some apps show the icon, some don't. But across devices, it's not the same apps.

What I've tried:

1. Clearing the cache for the Google Play Store


2. Clearing the data for the Google Play Store


3. Clearing the local search history in the Google Play Store


4. Completely emptying the wishlist in the Google Play Store


5. Reverting the Google Play Store to an old version, and allowing it to update itself

None of these techniques yielded any positive results.

What can be done to improve the Google Play Store to consistently allow the wishlist icon to appear for every app it displays?

(BTW, if you post a WFM comment, please also include your Google Play Store version number as well as the number of apps on which you verified the wishlist icon was visible.)