Why did gandhi ask britain to seek peace with nazi germany?

It's important to remember: few outside of Germany knew that concentration camps existed, certainly not the scale of them or how appalling the conditions were. Consider the amount of information that Gandhi could reasonably have about activity in Germany and Europe. As far as he was concerned, the evil empire dominating his country was just having a costly spat with the evil empire dominating another country, sacrificing the welfare of his people for those of their neighbours in Europe.

few outside of Germany knew that concentration camps existed
The creation of concentration camps was widely advertised in Nazi propaganda, as a show of force to intimidate dissidents. It was the later death camps that were secret: the ones that were designed for no purpose but to do murder at industrial scale.
- It wasn't an actual secret. All the Wehrmacht officers knew, all the people in the towns nearby knew, all the cops knew, all the Ally leadership knew.
good point

He didn't. The quotes in these tweets are fake. If I search for these quotes these tweets are the only results. Twitter is a hostile platform to reality as reality can get in the way of virality. Hence why you never see sources on twitter. This was likely written by someone with only a passing familiarity with gandhi's position on WWII who probably guessed at how he would speak based on his character in Civ.

What did gandhi actually think the Britiish should do in 1940? In his actual words:

I want you to fight Nazism without arms, or, if I am to retain the military terminology, with non-violent arms. I would like you to lay down the arms you have, as being useless for saving you or humanity. You will invite Herr Hitler and Signor Mussolini to take what they want of the countries you call your possessions. Let them take possession of your beautiful island, with your many beautiful buildings. You will give all these, but neither your souls, nor your minds. If these gentlemen choose to occupy your homes, you will vacate them. If they do not give you free passage out, you will allow yourself, man, woman and child, to be slaughtered, but you will refuse to owe allegiance to them.

Basically he was speaking for an extreme form of non-violent civil disobedience, not capitulation.

Also a famous gandhi quote: "Stop believing everything you see on twitter you gullible rube"

A lot of good that'd do for the people being rounded up to get gassed.
Gandhi was not always right with his beliefs.

the dude was a pedo
How is that related to his opinions on international politics? Just because someone is terrible in one aspect of their life, doesn't mean the rest of their ideas have to be thrown out.
he was?
- Debatable, I guess. Certainly by inclination if not necessarily a rapist.
  https://www.ibtimes.co.uk/ghandi-slept-grandniece-historian-tells-uk-government-1460499
  He did this super weird temptation trial thing, took baths them, etc. He took a vow of chastity when he was 38, but who knows what he was getting up to before then?
  I'd heard the niece was younger than 18 when it started but I don't know enough of the details to say that source is wrong. What he certainly was was a racist and a sexist... Who also ended the British Empire and they're still a bunch of salty racist sexists themselves so die mad about it.

Ah yes, the pre-emptive starving several years before the war

I don't understand your comment, the war started in 1939, Great Britain joined the war 3 days after Hitler invaded Poland. The famine occured in 1943.
Your maths is terrible?
- Oh sorry, I spoke about Holodomor.

I mean, it feels like the tweet explained it well (I know nothing of the subject, but if the tweet is accurate I don't feel it needs any more explaining).