Wireshark find why browser hangs


Some users browsers hang and timeout and I dont think it is a network slow down issue as internal traffic is fine and when some ping were sent over the internet while the browser was hanging the ping reponses were as fast as expected. only browsing is hanging. The fault could lie with the firewall or other devices interfering with web traffic & I need to prove which.

I have no experience with wireshark and Id like this to be a task for me to learn. I dont know how to interpret traffic for this purpose and I dont seem to find the specific info online thus far either. can anyone assist me?