No clue what's going on here. Today's last train from Aachen to Liège definitely terminates short at Maastricht. For tomorrow, only
www.bahn.de mentions the issues, while AVV's journey planner (
https://auskunft.avv.de), which is usually quite decent, doesn't say anything. Based on my experience I wouldn't be surprised if the services are cancelled at extremely short notice without alternatives. (AVV = Aachener Verkehrsverbund)
Some time last year, a RE18 from Aachen to Liège was advertised as being on time on the platform's departure board in Aachen, but the train simply didn't show up, with a confused crowd left standing in vain. Also no mention on the relevant websites. There weren't even announcements. Perhaps the railway employees were baffled as well.
SNCB's website is helpfully down for maintenance.
I have the feeling that this website is down way too often, at least when I'm in Belgium. The last time when I travelled in Belgium my train was delayed,
no guard on board I couldn't locate guard, and website down...
Edit: Thanks
@MarcVD for the correction with the guard.