Question: Due to my health condition, I have been advised by my doctor to shield and not to attend shul. Is there any preference to davening at the same time as shul?
Answer: The Shulchan Aruch (OC 90:9) writes that one who cannot daven with a minyan in shul should daven at the same time that the tzibbur are davening. The Pri Megadim (Eshel Avraham 90:17) notes that this specifically applies to the amida rather than the rest of davening. The Mishna Berura (90:30) adds that it has to be same amida. Thus, there is no advantage to davening shacharis while the tzibbur are davening mussaf.
The Kaf Hachaim (OC 90:64) explains that when the community davens together, it is considered an eis ratzon, auspicious time, when the tefillos go up together.
R’ Shlomo Zalman Auerbach (Halichos Shlomo, Tefilla 5:18) notes that this has to be a specific minyan. Likewise, R’ Yehoshua Neuwirth (quoted in Ishei Yisrael 8:n32) maintained that this applies specifically to the shul at which one regularly davens.
In conclusion, one who cannot daven in shul should strive to daven the amida at the same time as their regular minyan.