In my particular case dell mention the motherboard maybe damage and want to replace it.... at this point I will try to return it and get back my money, this is poor customer service.
Update: They don't want to offer a refund, at the same they hold no liability on the local company if they don't fix or mess more the laptop... this is horrible on several levels.
Another update. The BIOS team is apparently aware of this issue and is working on a fix. No ETA received, unfortunately.
Are folks still experiencing this issue? I haven't seen any recent BIOS updates to imply that this would be fixed.
I'm considering re-ordering an XPS 13 but would end up sending it back again if the problem isn't resolved.
I've been in contact with L3 support. They confirmed fix for 3rd party adapters should be in the next BIOS update. No ETA when that will be though.
Is anyone else seeing this happen on the XPS 15 9500? I started a thread where I'm having a very similar issue on that machine (USB-C to DP cables don't work with the TB3 ports when the monitor is in DP 1.2 mode): https://www.dell.com/community/XPS/XPS-15-9500-Intermittent-signal-on-4K-DisplayPort-1-2-monitor/m-p...
The main difference is that the XPS 15 has one non-Thunderbolt USB-C port, which does work as expected with my DP 1.2 monitor, but the issues with the Thunderbolt ports sound exactly like what I'm seeing in this thread.
Dell released a new bios this morning, v. 1.1.0.
I was under the impression that this issue was being worked on and fixed for the next bios update, but most display adapters do not work or only SOMETIMES work. It's disappointing to see this issue not fixed, especially as so many of us are working at home with docking stations.
@DELL-Cares can you please advise us on what to do? Are level 3 techs looking into this? It seems like a hugely basic flaw for a laptop to have...
@LiquidIce012 are you able to be in contact again with the L3 techs you mentioned earlier?