Healthy Association or Not?

Assalamu alaikum everyone.

I have a concern I wanted to address as a new Muslimah (90 days now! alhamdulillah). I realize that I am far from a perfect Muslimah as I am new and even then have things I need to improve on insha'Allah. I do, however, want to make sure I am doing things correctly in Islam and following it as purely as possible to avoid being led astray. On the other hand I don't want to be hypersensitive or too judgmental over other Muslims who may be at different levels of observance or knowledge in the deen. But I need healthy association to be able to grow in the deen. Here is what occurred that disturbed me:

I was at masjid recently for a class session followed by salat. After salat in the hallway I met some sisters who invited me out to lunch and indicated they were a part of some kind of a Muslim group but did not give me much detail other than that they are a social Muslim organization. They were going to a Middle Eastern food restaurant within walking distance so I agreed to join them. The moment we were outside the masjid entrance but only a few feet from it and still on the masjid property visible by many people, two of the three women abruptly yank off their hijabs and pull their abayas off over their head revealing very un-Islamic dress underneath with cleavage, short sleeves, etc. One of these women was the leader of this group and the other one was the leader of another similar group to be meeting in a few days at the same restaurant to which I was also invited. They were friendly but there seemed to be a lot of gender mixing with guys and girls even hugging, etc. I went online after the lunch to the websites for these groups and found out that for the other group that was meeting in a few days had their event cancelled and instead rescheduled for the restaurant during Ramadaan and during the fasting hours which made no sense as Muslims cannot eat during the fasting hours and how can you meet at a restaurant and not order?

I really want to make Muslim friends who I can grow with and understand not everyone follows Islam perfectly. Am I being hypersensitive here or should I consider this to be red flags and therefore unhealthy association and a group to avoid? I'm not trying to judge as I really don't care if sisters don't wear hijab, if they drink, eat pork, etc. but I do care when they claim to be leaders of an Islamic group and blatantly do these things in the public place almost as if making a political statement. Astagh-firullah if I'm being too dramatic here.

Jazakallah khair for any advice.