I've never come across flashing this card. I have a similar model network card and get up to 2mbps.
Does the hanging happen if you try and connect after rebooting? If so Matt_Hs advice about reset to overcome a Gayle bug will help, or you can get cheap hardware fixes.
Try Amispeedtest (off aminet) to measure your raw speed too.
What network services and apps are you using e.g. what web browser, FTP app etc?
The websites you connect to will also make a difference. Aminet.net is fast on an Amiga but something with loads of JavaScript etc will render by Christmas 2023 if you start now.
