Hey there, new here! I wanted to find somewhere I could get something off my chest and I guess see if my experience is mirrored by others. I'll keep it short and to the point. You'll have to bear with me as it's not directly parenting related. 
My wife does the pick up and drop off most of the time but several times a week I'll do one or the other myself. There are a number of other parents that me and my wife have become friends with over the last few years. We've all attended birthday parties and get togethers outside of school in the past. One or two I suppose we've become good friends with either through our children or because one or both of us gets on well with them. In these group environments things are fine. 
But something strange happens out of that group setting and I'm really starting to worry if it's me or I'm just looking in to it too much. 
Basically, on the days I'll do the drop off or pick up, it's as if I've put on an invisibility cloak. What I mean is I'll be friendly to other mums (rarely dad's) and say hello but sometimes that'll go unacknowledged. Now that could be deliberate or unintentional, I don't know for sure but it happens a lot and it's frustrating! 
I don't really understand it as mum's will happily chat to each other but it just seems too awkward or uncomfortable maybe to include a dad in conversation.
I might be overreacting to this as I have been diagnosed with social anxiety recently which I've suspected I've had for majority of my life and I've worked hard on improving that in recent months and come along strides. This experience though makes me question that improvement.
Do any other dad's experience the same? Like you're almost ignored by others on school run? And if it's not just me, then what about you mum's then!? Is there a reason for this? Is it just more awkward interacting with us dad's?
Thanks for reading. 