International site outranking domestic site, looking for advice

[kopendigital]

I have 2 versions of my site, one for my US company (vubastone com) and one for my UK company (vubasurfaces com).

Earlier in the year (around February) I did a domain change for the UK site around the same time I put the US version of the site live. My UK site was always ranking top for my keywords in the UK and since the changes it has completely dropped and doesn't show in searches, only the US does which is fine in the US but in the UK my UK site should be top. I've taken all the necessary steps such as:

• Redirected all URLs
• Setup href lang tags for necessary urls
• Registered the change with google search console

From my perspective I can't see any issues, that only thing I can think to do now is change the domain for the UK site to a .co.uk one. Merging both sites into one isn't an option.