Apple Watch S4 GPS- switching from iMessage to SMS

I have an Apple Watch S4 GPS. When sending a text message with WI-FI to an iPhone contact an iMessage is sent correctly.

When I leave WI-FI, the blue lettering Indicating to send an iMessage is still present even though it wouldn’t be possible to send an iMessage without WI-FI. The first night I had the watch this feature worked properly-after I updated to WatchOS 5.2 I noticed the following glitch. If I do send the message, a blue line appears in the upper screen and eventually I receive a notification indicating the message failed to deliver with a red explanation mark. I wish to send a regular SMS text to the iPhone contact when I don’t have WI-FI. It doesn’t allow me to, even though usually on my iPhone when I leave WI-FI it automatically switches from iMessage to SMS. Why doesn’t it do the same for my Apple Watch. I’ve tried everything toggling the iMessage on/off/on. Turning both my iPhone and Apple Watch off/on. Making sure the same Apple ID account is connected to both devices. I even did an online chat to no avail.

Basically, long story short..I want to know how to make the Apple Watch automatically switch from iMessages to SMS when leaving WI-FI.

Thanks to anyone that can help me. It’s very frustrating