Indecisiveness can be an issue with Librans. [not just Sun in libra, but an emphasis by Moon, personal planets and/or the Ascendant.]
My Virgo cousin has her Moon and Mercury in Libra. She is one of the most indecisive people I know. She is very intelligent but she over thinks things. She becomes overwhelmed by the possibilities.
And that sometimes leads to them appearing to be 'two faced.' Which is unfair because I do not think it is usually a manipulative or purposeful thing, that they may appear to be two faced.
I think they just try to be fair and impartial and polite, and in doing so, they tend to agree and comply with others, in the moment.
Libran energy can be very gracious and welcoming towards others.
But the shadow energy of that ^^^ is someone who is dismissive of others, judgmental of others and puts themselves in another league, above others.
Libran energy can feel as though they are entitled, and should be treated better than other randoms surrounding them.
I'm a libra asc, my bestfriend's a libra asc, her sister is a moon in libra and the guy she's talking to is a libra moon as well.
So I do think they tend to play the devil's advocate quite a lot, and probably doesn't have a stern stance on issues.
Let's say you have an opinion about something, that is similar to theirs a they've indicated a few days ago, (if they are absolutely comfortable with you), they'll try and make you see a different perspective. This often makes you think that they are not on your side and they're being judgmental/antagnoist/unnecassary for no reason.
If they are not comfortable with a group of people, they either shut up and listen as to not upset you or push you away completely or only converse about the things about the topic you agree with.
So in general the effect is either they are judgmental and indecisive, or they are two-faced. Also, unlike other flaky signs, they have a tendency to talk too much creating an additional antagonizing effect.
I'll give you an example: you say : "I think parents should offer more guidance to their children and spend more time with them."
-very broad statement which can literally indicate anything.
-Libra person: "Uhh, not really, I mean most kids these days are staying at home until they are 28 .....[Some other reasons.....more reasons] completely not really caring about what exactly or in regards to what exactly you meant when you said the statement.
-Meanwhile in the other person's head "Didn't they just say like 2 months ago, 'parents these days are more uninvolved than previous generations."
"And she's going on and on, Imma head out."
If they are not comfortable with you on the other hand or to those around you.
Girl 1 rants about the libs
Libra: "Yeah I see how they can be so sensitive and use identity politics.
Girl 2 rants about conservatives:
Libra: "I hate what trump is doing to the country and how he's propagating violence. "
Now the Libra may be somewhere in the middle, and may even believe both these things. But will choose to expose the part of her that aligns the most with the person she's speaking to.
Now me as a libra asc, sun conjunct neptune, I like to understand everything, everyone, and absolutely all sides. I have a very multifaceted view of the world, and it doesn't always do well with people with more simplistic views of the world whose views I try to enlighten or enhance.
So yeah that's what you need to watch out for.