This sounds like it may be a missing localization token after upgrading. I'd suggest comparing your current localization files in your custom viewset to those found in a clean installation. Since the value is empty, the most likely cause of this issue is either the token is missing entirely, or it's misspelled in the localization file.
You may want to do this, in general, to be sure your merging process after upgrades hasn't missed any other updates and localization tokens. https://hotcakescommerce....n-Upgrading-Hotcakes
Will Strohl, Upendo Ventures Hotcakes Cloud
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