If anything make it an option or add an option to change the size of the top row information. The 5G logo and positioning is the same size as the 4G. Don't see any value to change it and clutter up the top bar with a giant 5G logo. Just a personal preference.
transparent 5G icon means it's connected to 4G but it's telling you that the phone tower infrastructure you're connected to is capable of 5G.
Why is it not connecting to 5G? could be the distance, the phone will switch to 4G when it's a long distance. another reason is the 5G antenna is facing the other direction and not in sight with your direction.
A solid white 5G icon like mines means you're close enough to use 5G and the 5G antenna direction is facing near you. Solid white 5G is saying it's truly connected to 5G. hope I could help!