Native Conversion Rates Bad After 6pm Eastern?

For months when I was doing well, I didn't pay too much attention to dayparting, but I did notice that profits never seemed to get better after 5-6pm eastern, and on many days they would get worse

Now that things have gone south the past couple months, I have been paying attention to every small detail of my campaigns, and they are suck after the timeframe I just mentioned

Someone was telling me everyone he knows who runs native either shuts things off around this time, or they lower their bids dramatically


For the native advertisers out there, is this something you see as well?