Why is my dropdown list showing differently on phone than desktop and how can I fix it?

I have a normal select/option setup for a dropdown list and on desktop it looks like normal: https://imgur.com/6xaHjjd.

However, on the phone it instead uses some native phone list, something that looks like this: https://imgur.com/Avftd0N.

This could be all fine, the problem is that in some places I have made my own multi select dropdown list which looks like this: https://imgur.com/2n8SnsL. This list will show like this on both desktop and phone, since it is just made up of divs.

Questions

1. Can I somehow force all devices to use the same type of dropdown on a normal select/option setup?
2. Should I?
3. If not, would you recommend me to create my own dropdown lists too so that I get the same behaviour for both normal and multiple select dropdown lists? It is sort of ugle when one dropdown shows as e.g. native android and one as a “normal” dropdown on the phone.