If your domain is ccTLD (.co.uk) then geolocation of server didn't matter. Of course just need to be fast for that country where users will be.

Nadav,

this could happen in restrictive robots.txt where there are some enabled parts and other parts disabled for indexing.

But you help you could you sent link to that file so we can give you best advise for your case?

Both issues are on ALL WordPress sites.

xmlrpc.php return 405 because it's work under HTTP POST but bot crawl under HTTP GET.
And error 405 mean switch from GET to POST. But bot can't do that.

admin-ajax.php return 400 because it's not designed for direct use. You must make call with some parameter and it will return some information.
But as name says - it's responsible for AJAX calls and it's not for direct use that's why it return 400 when it's called w/o parameters.

So - that issues are not related to your issue.
For example mine WP sites also return same error codes to the bot.

Peter

There isn't proper way as you want it.

You can make .com and .co.uk country preferred with geo targeting:
https://support.google.com/webmasters/answer/62399
but this doesn't limit indian users that type english queries to see your sites in SERP. This is best way IMHO.

If you need true protection against indian users then you need to make some changes. You can get list of GeoIP database:
http://php.net/manual/en/book.geoip.php
and based on this code to give users access or stop them.
BUT this is very risky in real world since all bots comes from worldwide. Example - if you disable US IPs on .co.uk then you will stop GoogleBot visiting your site too. Also Roger will be stopped, Bing and many other bots. No bots - no ranking... This can be recognized as sneaky redirect.

So i don't recommend you to do this geo ip limitation without calculating all pros and cons of this.

That's correct.

Long story - there is hreflang in HTML head and in xml sitemap. What's the difference? In HTML you can use same-site or cross-site links (between domains), in XML they are only in same domain. So in XML sitemap you can't use cross-site links (between different domains).

Also in SearchConsole you can set "international targeting" (SearchConsole -> Search Traffic -> International Targeting -> Country) for different sites.

I know that hreflang is little bit complicated but once you setup your first site correct then on next sites will be much faster.

Is code on .htaccess works?

It should be on top because that file is executed from top to bottom. And if some rule must be executed then execution flow can stop so next rows can't be executed.