@BRONCOSCJA18 is this the only Solo Challenge (series) you cannot play? on what platform do you play (xbox, PC, PS)?
my first guess is that it might be related to a desync issue (i.e. the information that you already have fulfilled the criteria to play these Solos was not stored correctly. if you are playing on PS or xbox, I'd try to do a power cycle as doing that solves some issues (see details how to do it below).
my second guess (since doing it solved some issues for me recently): maybe there is something wrong with the cache. the game saves some information there to fasten loading processes. if the data stored there is corrupted .... maybe deleting / emptying the cache is worth a shot? (how to do it:
https://help.ea.com/en/help/faq/clear-cache-to-fix-problems-with-your-games/)
one more guess: sometimes, the current lineup causes issues like yours (i.e. not allowing to play some games). I've often read that creating a new lineup (e.g. by using the "generate best lineup" option) was helpful since sometimes there is something corrupted saved in the background of the lineup.
and one final guess: what MUT level do you currently have? I can't remember exactly, but maybe these Solos require a specific MUT level?
I hope one of the approaches is helpful (although I have to say that the described approaches are suggestions which are often made for diverse issues, so I'm not really convinced that they will be able to solve your issue too). anyways, good luck!
how to do a power cycle (taken from a post by EA_Aljo): >>> unplug your modem, router and console. After 2 minutes plug in the modem and router. Let them come back online completely. Then plug in your console and start it up. <<<