Is anyone having problems with the hubs they've attached to their 2020 MBP? I saw mention of this on MacRumours - people were saying their hubs were getting very hot and they feared damage to their hubs.
It looks to me that the heat of my 2020 MBP damaged my J5 hub. This hub is supposed to be designed specifically to work with the MBP. It started out giving intermittent signal transmission problems, but after a few weeks, it was giving major signal transmission problems. The Satechi hub I used before it also gave problems. Both hubs became hot when in use.
Here's the long version of the story for anyone experiencing similar problems:
I started out with a Satechi hub, but it wouldn't support a signal to both my external monitor and my backup drive. I noticed the hub would get very hot. When I called Apple Support about this, they did say that the laptop could be causing the hub to heat. When I talked with tech reps at Staples, they said the same thing and suggested I get a J5 hub.
The J5 hub snapped into the side of my 2-port MBP and so was able to sit on top of my cooling pad. I figured this would keep the J5 cool. It did keep cooler than the Satechi did- as long as I remembered to turn the fans of the cooling pad on. The J5 was also able to send signals to both my external monitor and my backup drive at the same time - but not completely; I would still experience a couple of seconds of blackouts of signal to the monitor several times a day.
And then suddenly the problem with the J5 started becoming much worse. One day the blackout lasted for 5-10 minutes. I checked and rechecked all connections. I thought my monitor must have died; but I plugged in my old 2013 MBP directly to the monitor and it worked just fine. I tried again with my 2020 MBP and this time the J5 sent the signal. Then, the next day, the signal from my 2020 MBP to my monitor (via the J5) was in trouble again. This time the words on my document were pulled out into long black lines and then my entire screen was filled with bands of coloured statics - like the snow of a 1950s TV set.
I need my MBP for work-from-home (COVID) and had to conduct 4 training sessions by Zoom in the next two days to teachers who had to be up and teaching on-line on the morning of the third day. I thought the problem might be my monitor and started investigating compatibilities and costs of new monitors. I started looking for a third hub, particularly at the Satechi Type-C mulitport adapter 4K which specifically said it was compatible with the 2020 MBP - but it carried this disclaimer, "We recommend connecting one bus-powered device at a time." So that meant that despite its three USB ports, I would not be able to plug in my monitor and backup drive into it at the same time either.
I called Apple practically in tears and they gave me a phone number to the manufacturer of my monitor to check with them whether my monitor was dying or was incompatible with my 2020 MBP. I talked with the monitor company, and they said it was most likely the J5 hub that was the problem and to not use the hub for the monitor, but plug the monitor into one of the two MBP ports on its own via a USB-C to HDMI adapter.
I ordered the adapter and replaced my J5 hub with the Satechi hub that I used at first - plugging only the monitor into the hub. This restored the signal to the monitor with no problems at all. So the J5 was the problem. But the question remains as to why the J5 worked for weeks (albeit with intermittent signal loss) before suddenly starting to fail. It does look like the heat of the MBP did damage the J5; maybe because the J5 plugged into the MBP and so sat directly alongside of it.