I like to meditate in lotus, but I usually have the right leg on top.
I’ve heard that your left leg should be on top due to the way energy flows in your body, and if you don’t you could cause yourself some health problems.
Anyone have any thoughts on this?
Switch it up.
I 2nd switching it up to balance left and right. I also favour one side (easier) so make a concerted effort to stretch the less flexible hip.
I’m more comfortable with the left on top 
While there may be some standard patterns, there’s also exceptions (left vs right handed?), other factors (geographical location?), and complicating variables (biological sex vs gender identity, etc.) all of which point to the idea of testing left or right leg on top and seeing which feels better for you. I don’t normally sit in lotus, but if it became more comfortable, I’d still switch it up, also for balance and physical reasons.
Traditionally the right leg is the only one that should be placed on top for spiritual and meditative purposes. It is associated with Shiva’s energy. For purposes of physical balance it is okay to switch up the legs if working with it in that context. Where is this left foot business coming from exactly?
I’m pretty sure whatever feels more comfortable to the individual is the best .