Position replication of models under network ownership of other clients is sometimes very laggy

[NotAstrain]

The planes in my game Navy Simulator have become very laggy when viewed from other clients. In the best cases, the position of the planes appears to be replicated at 10FPS. In the worst case, the planes appear to freeze in midair for seconds at a time. This can be seen in this video: https://www.youtube.com/watch?v=IBII2KqcJnk

Some specifics about this bug:

• This issue started sometime last week. Before then, the position of the planes was replicating smoothly and there were no issues.
• The two planes in the video seem to be lagging at different times than each other, and the ships in the background still keep moving even when both planes appear frozen. This indicates the issue is not due to an overall ping spike.
• Both the ships and planes are moving, unanchored assemblies. Each ship can have hundreds of parts welded together, while each plane only has less than 100 parts. The ships and planes almost always have their network ownership belonging to a client, and not the server.
• This issue happens even when your character is close to the affected models.
• This replication issue sometimes also happens to ships, but not nearly as often.

Reproducing the bug seems to only be possible in a full server. The link to the game in question is ⚓Navy Simulator - Roblox

[NTL331]

The same thing happens in my train simulation game.
I decided that there was a problem with the streaming settings and tried various settings, but nothing worked.
Of course, there is no lag whatsoever in Studio.

[subcritical]

Hi, can you check if this is still happening? We’ve disabled a test that might have caused the jitter.

[NotAstrain]

The freezing is fixed, which was the main issue.

It seems that since this problem started, there’s still a notable drop in the framerate of vehicle’s movement, as if they were moving at 15-30 FPS in contrast to everything else. I believe this is interpolation throttling:

New Optimization Feature: Interpolation Throttling

Introducing… Interpolation Throttling! This new optimization feature may improve the performance of games with large maps and lots of moving parts. What does interpolation throttling do? It reduces the update frequency of all remotely owned mechanisms outside a client’s simulation radius. So, parts that are far away from the player, and they don’t own, will step at 30Hz. It only kicks in if the engine detects that updating and interpolating remotely owned mechanisms is taking a long time. F…

Interpolation Throttling Update

As of 1/6/2022, Interpolation Throtting enabled by default. You can still opt-out by setting the Workspace property to Disabled. If you need to do so in your experience, please share why below. We’ve enabled an update for Interpolation Throttling, a feature which can improve client performance by reducing the number of network updates. Interpolation Throttling can be especially helpful for experiences that have large maps and lots of moving parts. Please read the initial announcement if you h…

Interpolation throttling used to be opt-out, and on Navy Simulator we disabled it to keep the movement of vehicles smooth. It looks like the property on the workspace used to opt out of it has disappeared (workspace.InterpolationThrottling) and it’s now enabled for all games. It’s not great for our game since a lot of the time you’ll be standing on someone else’s network-owned ship. Is there anything we can do about this?

[vespa_rbx]

Could you provide an example of what exactly you mean? Is it visible with ships and airplanes or some specific type of vehicle only?
I’m trying to confirm that the issue is possibly related to interpolation throttling

[vespa_rbx]

My current theory - the possible jittery movement of a vehicle is not related to interpolation throttling, but rather related to the vehicle owner-client’s low FPS.
When FPS drops below 15, the position updates to the server and other clients get too infrequent and as result, interpolation simply does not have enough data to produce a smooth trajectory.
Thus, on a non-owner client vehicle may appear jittery while interpolation is waiting for a new portion of the position update

[NTL331]

This is a video recorded in my monorail driving game.
Please pay attention to the train approaching from the back at the beginning of the video—it appears to teleport every second.
However, it seems to improve somewhat once it gets closer to the player.
I thought it might be due to my network environment, but since other players have reported the same issue, I believe either my game settings are incorrect or it’s a Roblox bug.