Need some advice on still rejects

So earlier this week I submitted some shots of fireworks going off. I shot them using a tripod and a remote trigger release. The camera was never touched and it was not at all a windy night. All of them were excepted to other stock agencies in total. Not one single rejection. Then today I got back my review here on pond5 and every one was rejected for blurring. Has anyone had similar issues. I moved the luminosity slider up in lightroom to around 50% on most of these to cut some of the noise, could that be the problem. I really like this site and have had all but one of my footage files excepted but I would love to upload my stills too. Any ideas about how to fix this issue would be appreciated.