Hi, 

from 11 Dez, like every second sunday in December there is the yearly timetable change in Europe. Eurail.com and the app are the last one that get up-to-date. Check the website of the train company that run the train (in your case, Belgian rail SNCB/NMBS https://www.belgiantrain.be/en), there you will find before all other places an timetable update. Keep in mind that some trains can still miss, due to not finished timetable or due to planed works on track. 

Besides this explanation it is also VERY unwise to add those trips so lang advance-anything can happen and we see here dozens of problems/complaints from people who did not do that. Plus that all these trips are without any needed or even chance to RES anyway.

For trip 1 avoid these superexpensive Thalys-just use the hourly BeNeLux train and change Antwerpen.

Do note that this 23/12 is likely to be a very busy day-just before Xmas and FRI-so the ICE BRU-Kóln-always already prone to delays and cancellations at very last minute-can RES via bahn.com for 4,50/seat only-but even then expect it may be cancelled later. DO familiarise yourself with the ALT via the slow trains (change Welkenraedt and Aachen) or use them str8 away.

The new timetable is not yet in the planner (also not the Belgian planner on the link @Angelo gave).

21st and 23rd of december are weekdays, so there shouldn’t be much difference to the pre December 11th schedule. On weekends there are often works, although usually not on the Christmas weekends.

When you book your reservations, avoid Thalys (very expensive) and take the ordinary IC-train (no reservation needed). 

You can expect the direct trains from Antwerp Central to Bruges at +/- hh:06 and takes one hour and a half. The new timetable usually only changes times with a couple of minutes. You can take other trains to Gent-Sint-Pieters and change there for trains to Bruges. Doesn’t take much more time, but a bit of a hassle if you have lots of luggage.

Don’t forget to admire the station of Antwerp Central, trains to Ghent-Bruges-Coast leave on the upper level. ;)

The ICE services seem to be a bit more reliable again the last weeks. The rain of cancellations stopped. This summer they were an absolute disaster. They have difficulties with the heat. But reserve them right away! Now you might still find free seats. 23/12 is gonna be a very busy day on the European rails! Everybody is going to head home for Christmas, added with last minute shoppers, German Christmasmarket go’ers and holiday makers.

Thanks for the answers and advice everyone. Much appreciated! 

@Patrick-oliver 

In about two weeks the Belgian schedules will be available. A bit later than usual. So you can check again then :)