I'm not all that tech savvy but I think it has to do with Visible using VoLTE(voice over LTE) but not 100% sure about that. I don't use my phone much for calling so I haven't noticed that since Visible upgraded the system from the cloud based server system to the Verizon core system in the fall of 2022. I know some calls back then acted like that, even calling from my landline to my brothers cell phone would do that. Also, I am on Android and my sisters have iPhones but again rarely call them, text them instead, but thought the last time I talked to them it worked normally and not cut out.
I would be guessing but it could have something to do with the network or maybe even the area the android person is in. Try ask that person that has the Android phone if they have issue talking with other iPhone users. My guess is likely not unless they are on a carrier that is using VoLTE.
Sorry, I couldn't be of more help and hopefully this kind of answers your question. There are not many users on here that visit and comment but maybe someone will see this and can explain more. If you are a Reddit user visit the Visible page and maybe post this question on their. There are thousands of more visitors on that page than here.
