Yes but you showed something in developer options. That takes 2 things from the user. 1 to go into developer options and then to enable that.
On a stock phone that won't matter as much. As I showed above mine does the same thing and I've never once gone into developer options.
Second.. mine used to keep the LTE icon white (active) when I had the caller ID app enabled since it needs the mobile network to ID. After disabling it and rebooting the icon now goes grey (inactive) as shown in my screenshot.
I promise you it's using WiFi. This issue isn't new and came around the S6 area. I've dealt with it a bunch

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