Need google analytics expert to fix real time traffic problem

I have a swimwear company and we use shopify, I have had google analytics working for several years and regularly look at real time to see how many users are on the site. However ever since yesterday afternoon the number of real time users has dropped significantly and it barely shows any users active on the site now.

I don't know if it has something to do with the new google analytics 4 property which I have tried to set up. However it only shows that a few users are active throughout the day now when it should be a lot more. I can see with live view on shopify how many users are active on site and there is a lot more than what is showing on google analytics. Not all users are missing but only a few are now showing as active which is very odd.

I really need someone very experienced with google analytics to fix this for me.