Will poor cellphone connection during screening call affect my chances?

Use wifi calling, that's what I do!

Also as a rule of thumb always call a friend via the interview method before any interview to verify call quality. I do this if I have a teams interview and ive never used it before and so on

https://support.apple.com/en-us/108066

https://support.google.com/phoneapp/answer/2811843?hl=en

Even in the United States, cell signal can be quite patchy. Literally in my own house, I get near 0 cell signal and I need to rely on wifi for everything (I use wifi calling as Sai mentioned). The harsh reality though is that this isn't the employer's problem at the end of the day, and it's on you to make things work.

As Sai mentioned, use wifi calling. Here's some other tips:

1. Try to move the interview to a video call instead of a phone call - You have more screen real estate on a computer compared to a cell phone, and computers are more powerful than cell phones in general.
2. Do a sanity check before the interview - Whatever the interview format is (phone call or computer video call), have a friend call you 30-60 minutes before the interview to do a test run to make sure that things work.

If Meta has given you another chance, you are probably starting from a blank slate for the next round. I doubt you will have -10 demerit applied to your packet or anything. Make it count by making sure everything goes as smoothly as possible, especially your connection as that's table stakes.

For tips on passing the Meta interview, check this out: "How does the Meta interview work?"

You want to make sure everything is in your favor during your interview especially since it's so high leverage to be able to get the job offer. I also agree with Sai and Alex about using wifi calling (and checking to make sure wifi calling is stable and clear).

I've given interviews where the other person's connection is unstable, and they connect/disconnect frequently. It does alter the experience of the interview experience because it's harder to stay focused on the solutions that the candidate is proposing.