Would you mind detailing? I have never encountered that kind of issue, so I'd love to learn more.
any broadcom networking hardware, on debian it will constantly drop out @10Gbps link speed on copper is one such case that I can describe. But over the years there's been plenty of related issues with e810's and whatnot. Disks, disks will also stall or drop out which doesn't happen on ubuntu kernels.
Do elaborate.
vendor oem's shipping broken firmware, enterprise customers complain to ubuntu, ubuntu fixes it in the kernel driver