well but the options to support their relationship are always not clickable for me. i tried siding with cindy or with wade or both of them or leave them alone for a bit but nothing i did so far enabled me this option
The first step to help their relationship is to tell Wade "
You need to fight for Cindy" in ch.4, which requires Ian to have Charisma of 3+ and for Ian not to show too much interest in Cindy (don't comment/like her picture, don't flirt with her etc)
This enables Ian to tell Cindy she should bring Wade to the photo shoot instead of going there himself. If you don't, stopping Wade afterwards from drunk-calling Cindy (or confessing about Ian's involvement) keeps the relationship somewhat stable. In any case this can be improved further by asking "
Do you really want to be with Wade?" in Ch.9, provided Ian didn't kiss Cindy.