Who is responsible for disputes between Megha and Sai??

I think Sai and pushki both.

I think Sai. More than Puskar, Sai herself is responsible for this fiasco.

at the start -
all the Colors actors - Aastad, Bhushan, Jui, Smita . Sushant, aarti immediately joined Ra & Re . These then kept aau & Vinit under their thumb .
Thatte , initially made some noise but later on joined Ra & aastad.

So , Others Sai , Megha, Pushkar, Rutuja had to come together.
It was clear to Megha that the only chance of their group surviving is by viewers poll.Her strategy has been to get viewers likes & approvals. Sai & Pushkar never understood this.Pushkar has always tried to be in good books of Resham Group& Sai's image of spoilt girl is getting bigger each week.So many viewers consider that Pushkar is playing double game & Sai, by following him . also getting dislikes.

Now , we have Re, Sushant,Bhushan , Jui , Smita & Nandkishore & Tyaagraj together. In the precap ,Nandkishor is scolding Sushant, But I do not give any importance to it . His selecting Sharmishtha to be no 1 over-confident person , is IMO , shows that he is on the side of Resham group.
While -Sai ,Megha, Sharmishtha , Pushkar on other side.
Aau never talks when she is needed most , so better count her out.

My take is , BB has always kept the game loaded in favour of Colors actors. So , all the time Megha's group will be nominated & people have to choose one from that group only.They have also kept the tasks in such way that Madha group will always be underpowered.

good sai don't trust megha anymore.megha is very cunning she is just using sai to go ahead in game.she was manipulating pushkar to support sushant in captaincy task but pushkar denied as he has brain and he doesn't trust megha.how easily megha forgot it was sushant who threatened sai to damage her face while she was supporting megha in captaincy task.

Nobody is responsible. 😊

I think they have buried the hatchet and are back together.. so all is forgotten. that said, this is the second time, sai appeared to get easily brainwashed.. I wont be surprised if she joins resham n gang in the very near future... believing that move to be good for her own game. and pushkar will wholeheartedly support her in that.