The current (somewhat impractical) MS recommended work around for the multiplayer stutters introduced with the last patch is that everyone visible on your server has to fly default aircraft with default liveries.

Unfortunately if some random turns up at the next airport in a CRJ or corsair or in the WT CJ4 or with a fancy custom livery all bets are off, but so long as you are all flying default with default liveries it actually works, no multiplayer stutters.  Floating name tags in the distance seem fine, it is once the other players aircraft becomes visible that you get stutters.

I am not sure if premium or deluxe aircraft count as "default" probably not.

The other option is of course to turn multiplayer off.

Edited April 22, 20215 yr by Glenn Fitzpatrick

This is one more reason the following topic must get more votes and get more attention:

Multiplayer: display other players actual aircraft 3D models and liveries around you - Self-Service / Wishlist - Microsoft Flight Simulator Forums

Thanks for this information! My son and I tried a multiplayer flight on Monday and my son had a stutter-fest with me flying a C-172 with a non-default livery. Tried again on Tuesday with my son flying a non-default livery and I experienced the stutter-fest. We finally figured out it was the non-default livery causing the problem. Happy to know it wasn't just us! Thanks!