Q. I heard that Horav Miller Shlit’a changed yesterday (4/19/20) his ruling in regard to minyonim in the backyard, is it true? What is the new ruling?
A. As mentioned in the last question, Covid’s sole true constancy is its ability to change. I spoke to the Rov Shlit’a this afternoon (4/20/20) and indeed, he maintains that for the time being, people can attend a front porch or backyard minyan, only once a day, for Mincha, and when davening a “hoiche shemonesre” (without the repetition of the amida), followed by one single kadish yosom.
No taalis should be donned (so not to provoke unnecessary feelings of “eiva,” (dislike) with the neighbors.
Essential conditions are that only the people dwelling in those houses are permitted to be part of the minyan, no visitors are allowed and the safe recommended distance must be always maintained.

Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit’a

In a letter send by Horav Shlomo Miller Shlit’a on Nissan 27, the Rov wrote:

•  Each person must stand on HIS porch only
•  NO gathering in any yard
•  NO outsiders may join at all

If these guidelines are not followed, then there would be no choice but to ban even porch minyanim.

Since in halacha a minyan of people on adjoining porches is unclear, one should not daven Chazaras Ha’shatz or kriyas Hatorah since it is a safek bracha l’vatalah. Therefore, this minyan should only be formed at mincha, with a short Shmonei Esrei in order to say kaddish and Kedusha.

One should also be careful that either everyone should see the Chazan, or the Chazan should be able to see everyone.