New MBP 13 1,4 i5 Laggy when WiFi is connected

[bigmater]

Hey guys I was an avid reader here ... but a recent problem finally got me to signup

New MBP 13 1,4 (Summer 2019) a few weeks old. Runnig MacOS Mojave 10.14.6. All worked fine until a few days: computer behaves laggy now when being actively connected to a WiFi. You can feel this already when starting an application like Chrome or Visual Studio Code (or put any other application here). Launching an application now takes 3-4 times as long and then applications behave just no longer snappy. Not super slow but no longer as snappy as it should be. The whole computer just feels slower like thermal throttling kicked in.

If I disconnect from a WiFi network the Mac behaves as fast as before with all applications launching super fast and running smoothly. I can really demo this bug back and forth by just switching WiFi on/off or at least disconnect from the WiFi network. It is not related to having WiFi in general swiched on or off but when I am actively connected to a WiFi network then the computer starts becomming laggy immediately.

I have tried 2 different WiFi networks. Problem occurs exactly the same. I restarted multiple times, checked if any termal throttling appears ("No thermal warning level has been recorded") and also checked activity monitor for CPU load. But no increase of CPU load is visible at any time when connecting to a WiFi and experiencing this "laggyness".

I remember a few days ago I installed a Mac Security Patch which could be the same time the problem occured but this is super vague guess. I just want to mention it.

Btw. Just tried a similar speced MBP 13 1,4 (also with Mojave 10.14.6) from my girlfriend and exactly the same behaviour occurs.

 

[jerryk]

When connected to the internet many applications will check for updates when they first launch. And it takes time to connect to the servers, make a request, have and associated data downloaded, and the application.

This obviously is effected by the speed of your internet connection. What does Speedtest.net show for your connection. Post both mb/sec and ping times.

 

[bigmater]

Hey jerryk, thanks for the quick reply. I know what you suggest but I have Littlesnitch running and monitor up and downstream. Even when starting applications that do not check for updates and with no internet traffic at all this problem occurs the moment I connect to a WiFi.

 

[jerryk]

Hey jerryk, thanks for the quick reply. I know what you suggest but I have Littlesnitch running and monitor up and downstream. Even when starting applications that do not check for updates and with no internet traffic at all this problem occurs the moment I connect to a WiFi.

Does it work OK using the wifi in other locations? Might be something local, like a nearby neighbor stomping on the wifi. Also, does the problem occur if you use an ethernet cable to get to the internet?

 

[bigmater]

Different WiFi at other place same problem. Also tried hotspot via Phone which I normally do fine also same problem. It really started to occur the last few days. Never had anything like that. I did a speedtest just to get your theory also out the door

ping: 5 ms
download: 52.06 mbps
upload: 22.43 mbps

Edit: I have no usb-c to ethernet cable to test.