For sending things to devices I use KDE Connect. I realize it is a fundamentally different application, but it is what I use generally to send / receive links between devices, as well as documents, images etc. It also is good for notification mirroring, and really just integrating Android devices into Windows / Linux computers.
For passwords I used KeePass (and I sync them between devices with SyncThing), but I usually recommend Bitwarden (which is what I used to use). Both are open source, have apps for all platforms, can integrate into your browser if you choose. The main advantage of Bitwarden is that it is open source, all necessary features are free, and you can host the server yourself if you want. It also integrates into some services, notably email aliasing ones, to allow you to generate new emails every time you make a new account.
For bookmarks / history your best bet is the extension everyone else is recommending here!
I’m not surprised by the corporate network, it’s pretty common for those types of networks to severely block inter-device LAN communication. There are two solutions however, for one, KDEconnect has initial Bluetooth support. I think it only support Plasma and Android as of now, and could be documented better, but it does avoid the LAN access problems. The other solution is using a VPN, the easiest off the shelf solution being Tailscale, but I feel this is only worth it if you have multiple use cases for it (I use it for faster Syncthing transfers, Moonlight / Sunshine game streaming. And KDEconnect)
I really wish KDEConnect “just worked”, similar to how Apple’s devices connect to one another, but I guess this is the price you pay sometimes for an open source cross platform solution.