This could very well be because you have exceeded your Sandbox limit. I see that you have 0 available and you are using 2 full sandboxes. Do you pay for 2 full sandboxes? When you exceed your limit, SF doesnt allow you to refresh any of your sandboxes, not just the sandboxes in question.
I'm guessing that you have exceeded your limit and need to consolidate and/or change a full sandbox to a developer sandbox to fix your issue.
From SF Help
Salesforce deactivates all refresh links if you have exceeded your
If you have reduced the number of sandboxes you purchased, but you
still have more sandboxes of a specific type than allowed, you will be
required to match your sandboxes to the number of sandboxes that you
purchased. For example, if you have two Full sandboxes but purchased
only one, you cannot refresh your Full sandbox as a Full sandbox.
Instead, you must choose one Full sandbox to convert to a smaller
sandbox, such as a Developer Pro or a Developer sandbox, depending on
which types you have available.
See here for more information