SSH connection failure

Hello friends, how are you?
I’m using VyOS 1.1.8, normally, but some days, the SSH connection is failluring, reporting this message on Putty, and changing SSH client, same error:
Network error: Network error: Software caused connection abort
And I can’t connect on VyOS. So, how can we fix this issue? If reboot VyOS, the ssh connection be ready, but after some days, blocked again. I checked and had a subnet (customer) that had static loop, but don’t have more, this issue.
Thank you so much,

With Best Regards