While others have a weak left side DRL, I've no DRLs at all on my 2019.

When I got the car the headlights didn't work. No DRLs, no headlights, no turn signals up front.

The left headlight is full of substantial condensation and there's a hairline crack in the lens that I suspect is letting the water in.

I found both of the headlight fuses were blown. I changed the one for the right headlight and now I have a working right turn signal and working headlight, but the DRL hockey stick doesn't light up.

The left side immediately blows any new fuse I put into it, so I suspect the condensation is causing a short to ground. I've ordered a new-to-me light that will hopefully resolve this problem.

However, can anyone advise as to why the right headlight DRL isn't working even though the right headlight assembly is getting power and everything else works? Are the DRLs powered in series rather than parallel?

 

Modern headlight's do not like moisture and if moisture is left long enough, they will kill them or corrode the wires so bad it does not work..
I would also check the headlight connectors and look for signs of corrosion.
For my XK, I drilled a hole on the side of each headlight and glued a short tube in the hole to let out the moisture on hot days and then after a couple hours I would cap it.

 

Which is why I'm changeing out the left headlight assembly.

I appreciate your reply, but my question was why the right DRL - the one not exposed to moisture - doesn't work at all when everything else in the right assembly does.

 

This is a good idea. Many of the cars I own have this feature on the headlights from factory. It's a bit surprising that Jaguar / Valeo overlooked this.

 

That is why I said check the connector for corrosion and if the fuse blew, it could have killed the good headlight with a electrical surge,