Im trying to do a 2x2 split with my party of 4 as well, keeping the same 2 legs on the same date. Cannot do this on ua.com, no option to just split without changing flights.
Regardless, if I have a rep do a 2x2 split, will I then be able to select Exit row E+ for two of us that are age 15+. Right now, one person in our party of four is 14 and I think that is why I cannot seat ANYONE in exit row E+, I am being blocked from selecting. Am I thinking correctly on this?

Honestly, if that exit row seating in the only reason why you want to split the PNR then I would first try and call in to see if an agent can assign 3 in exit row and then 1 elsewhere for the ineligible pax.

I hear you.
I ended up changing flights before dealing with any of this so now moot, but hopefully the dialogue was helpful to someone out there.

Yes...the beta in the app wont work when trying to link two award reservations. Hope that gets remedied.

I have been linking two paid reservations for a while.

Maybe this belongs in another thread....as a Silver was originally on the same PNR as my other 3 family members for a flight tomorrow. Went through online check in and got to the point where I requested myself and one of my non status companions be eligible for the upgrade list. Completed check in. Knew that my MSP-ORD flight was practically empty in F and both of us almost certainly would be upgraded.

10 mins later...got the text you've been upgraded. However. I was the ONLY one split off to the new PNR, for some reason my companion did not pull through. System error or something. I tried to reconcile on chat but they said no dice cannot reconcile now. They did seem to admit the system error. I asked for the rest of my family to be moved to E+ with waived fees to comp, and the chat rep agreed. So now, I am in F and the other three in E+

Can I check with the gate agent to see if a companion can be pulled up to F when we get to the gate?

Is this a system error that occurs often. Totally frustrating.

Per 201 above....gate agent got this recified and got my companion into F with me. Im not going to wait until t24 check in again in the future, Ill pre split in lieu.

I'm flying with one companion tomorrow on an award ticket with two segments. We both got upgrade T-48 on the first segment, no split. We were #1/#2 on the list for the second segment. However, when checking in, there was no option to split PNR. About an hour after check in, it split, I got upgraded, and my companion disappeared from the list.

Sending a message to United on chat gets: "Thank you for confirming. I have checked here and the reason why your companion was not upgraded is because the upgrade list has already been closed. It is no longer available for any further upgrade requests. Im sorry for the inconvenience."

I mean, this cannot be correct, right, the flight is in 25 hours? Is there anything I should do? Would be nice as is a 3 hour flight with 4 seats available and only 3 people on the list, so likely to clear.

I would call in. Chat support seems to still be greatly inferior to phone support.

Thanks - it took them about 30 minutes but they fixed it. Upgrade already cleared! Phone agents were great.

Seems the most prudent thing to do is look around T48 and if reasonable chance to clear, and you are ok with any separation from other travel companions, to pre-split the resi.