Lagging in what way? Compared to what? Are you playing the same source to multiple rooms or do you have them grouped? 
You really need to give a bit more info if you’re asking for help. 

If what is happening is this: After updating to 14.18 some grouped zones start to fall out of sync  - then it’s probably the 14.18 update as acknowledged by the support team.  A temp fix is to un-group then re-group all zones you want to play the same source (over and over as this fix sometimes lasts less than an hour or so).  May not be happening on all systems, but is certainly happening after the 14.18 messy update. 

Suggest sending a diagnostic before and after the issue appears to support. 

Mine updated on Nov 10th and it's the 14 19 update 

I don’t think that issue that you describe is, at least from my guess, what the OP is describing. I suspect what their actually experiencing is some sort of network / wifi interference  which is causing lag when they’re sending commands from their controller to their speaker.

If that’s the case, I’d recommend at the very least, a network refresh, by unplugging all Sonos devices from power, then rebooting the router. Once the router has been back up for a couple of minutes, plug back in the Sonos devices.

Your “falling out of sync” issue is likely a more deeply rooted issue, since, at least from my perspective, the Sonos devices are loosing their ability to share timing information from each device across the network for some reason. I suppose it’s possible that it’s that same network / wifi interference , but seems unlikely, based on the various posts I’ve seen about the issue. 

I’d certainly agree that if that’s the issue the OP is talking about, a diagnostic submission, to give Sonos more data about it, and a phone call to get them to look at the diagnostic to be able to forward to the engineering team would be ideal. 

For what it’s worth, I don’t think there’s been enough time between the initial reports and now to both figure out what the actual bug is, get it fixed, and tested for release yet. I’m unsurprised that it’s not yet fixed in the release from yesterday. The real question, which Sonos has never answered on anything, is whether they’ve been able to identify/reproduce the bug locally, which gives them a leg up on an actual fix. We’ll have to see. Wish I worked at Sonos to know these things...but then I’d be bound not to share them here on these forums :)

Within the last 3 weeks it's been acting up, I rebooted everything like suggested already and have submitted my diagnostics and there are no issues with the internet

Perhaps describe your network/hardware and Sonos system - provide some detail such as the WiFi channels and channel-width in use on each band. Also, have you tried switching the system over to a SonosNet connection instead, to see if that resolves the issue?

Also, after submitting that diagnostic, did you call Sonos Support directly to discuss it? As they’ve indicated in the Diagnostics - How do they work? thread, they don’t react to a diagnostic submission unless you poke them.