I have the same problem. I use chrome for a VPN connection for work. On kk it would without any issues. Since the update to lollipop, I get booted off the VPN 20-30 times a day. I can't use the native browser because our work site is set up for cross platform, with only chrome supported.
I also use the native browser for filling out forms and if I don't have everything saved to my clipboard so I can just paste all the info into the fields, the page refreshes and I loose all the info I entered.
Tried using Pulse Secure for the VPN, but it only allows 1 page at a atime, and I often need 3-4, or more.
I have a 32Gb card with my files and apps on there as much as possible, and 16Gb onboard, I always keep my cache cleared (not clearing while I'm online, lol) but for the past couple days I've actually resorted to using an old iphone4 <shudder> tethered just so I can stay on the vpn.
Several people I work with are having the same issue. It's confirmed the problem isn't with the VPN, it is the actual devices, and it's all since lollipop.
I can't kill JavaScript, as I need it for the sites, I've gone into developer options, and tried everything there. Chrome debugging didn't work.
Please!!! I'm begging you for any help! I want to stop using that iPhone! Lol