According to The Sun (I do take it as a pinch of salt), a new book,
Left Out: The Inside Story of Labour under Corbyn, revealed that Harry and Meghan sent a personal letter of thanks to Jeremy Corbyn and his wife, Laura Alvarez. Both couples met at the Commonwealth Service. Jeremy and Laura allegedly gave them 'a book of verse by the 17th-century Mexican poet Juana Inés de la Cruz, “a nun whose willingness to attack the hypocrisies of the colonial classes had made her a target for establishment hate.”'.
Link to the Sun article:
https://www.thesun.co.uk/news/12478271/jeremy-corbyn-meghan-markle-prince-harry-book-poetry-megxit/
Like I said earlier, I do think this is just a publicity piece for the book
Left Out: The Inside Story of Labour Under Corbyn by Gabriel Pogrund and Patrick Maguire, due to release in 3rd September. But naturally, other opinion writers from political publications have picked it up.
The Spectator, not surprisingly very negative towards Harry and Meghan. It is behind a paywall, you can only read the first paragraph. This is a right-leaning, mostly pro-monarchy magazine:
https://www.spectator.co.uk/article/when-corbyn-met-meghan
Spiked, where the writer Tom Slater (also Deputy Editor) is a republican (anti-monarchy), centrist and a free-speech activist:
https://www.spiked-online.com/2020/08/24/of-course-corbyn-sided-with-meghan/
Since the conversation is private, I don't think this is "muddling with politics", but more like emotional support, similar to Diana and Tony Blair relationship, based on Tony Blair's autobiography.