Why can't I SSH in to an IP address that I am able to ping successfully? (mssfix doesn't work as a solution)

I’m running Ubuntu 18.04, and I am attempting to SSH in to an IP address on a server that I have connected to using OpenVPN. Note that I have been able to ssh in to the IP address via PUTTY on my Windows laptop, but this is not the case on my Ubuntu machine. On my Ubuntu laptop, once I’ve connected to the VPN I am able to ping the IP address without a problem, but when I try to run ssh -v username@ipaddress I get the output:

OpenSSH_7.6p1 Ubuntu-4ubuntu0.3, OpenSSL 1.0.2n  7 Dec 2017
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to 10.1.50.11 [10.1.50.11] port 22.
debug1: Connection established.
debug1: identity file /home/ellie/.ssh/id_rsa type 0
debug1: key_load_public: No such file or directory
debug1: identity file /home/ellie/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ellie/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ellie/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ellie/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ellie/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ellie/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/ellie/.ssh/id_ed25519-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_7.6p1 Ubuntu-4ubuntu0.3
debug1: Remote protocol version 2.0, remote software version OpenSSH_8.2p1 Ubuntu-4
debug1: match: OpenSSH_8.2p1 Ubuntu-4 pat OpenSSH* compat 0x04000000
debug1: Authenticating to 10.1.50.11:22 as 'ewhite'
debug1: SSH2_MSG_KEXINIT sent

It hangs at the final step. I tried following the steps here Setting correct MTU for OpenVPN and found that the MTU was 297. I set mssfix at 250 and tried to re-connect to the OpenVPN server then connect to the ssh again, but the outcome was the same — it got hung up at the ‘SSH2_MSG_KEXINIT sent’ step. Do you have any advice on what could be going on here / how I could fix it? I’ve searched around on Stack Overflow and elsewhere the best I can but so far none of the solutions that I have come across seem to work. If I can clarify any of the above / provide more information I’d be glad to. Thanks in advance for your time and help!