It seems that Eurail doesn't get the train timetables for those two countries. You'll have to search for the times in the countries own travel planners, then enter the journey manually in the Interrail app.

(BTW, seat61.com has some advice for those countries as for almost everywhere)

More advice: forget using a pass over there. Local tix will be much cheaper anyway in LV-and connections between LV to EE are very bad with hours wait at some tiny village @ border. Sensible people there go by bus. There are also NO treni from LT=Lithuania till LV=Latvia.

One can only get out of a site if someone has ever put that in-these countries are not yet that far advanced that they release their own data in common EUR sites. Maybe later-or maybe they think that noone would use their trains anyway from so far away. There are also in this forum some reports that in EE (where all tix are sold on board) passes are not recognized due to probs with the codes and you are then still forced to buy normal ticket. But maybe that was incidental.

Riga  Tallinn by train:

https://www.seat61.com/trains-and-routes/riga-to-tallinn-by-train.htm

Lux Express buses give a discount (no travel day needed):

https://benefitsportal.eurail.com/benefits/lux-express/

The issue is not to find the timetable in the planner. Timetables can be found on the website of the local train company, indeed. The issue is that I cannot enter the name ‘Riga’ to create a trip manually in the digital pass, since the city name cannot be found. So the real issue is that Eurail is claiming that the global pass is valid in Estonia and Latvia, but there is no way to create a ticket digitally on the pass for these countries. I don’t want to take a bus, I want to take a train, because I paid for it when I bought the pass… Any solution?

You add the journey manually, it’s always an option (fortunately !).

Thanks for the answer. I will try that and let you know if this is accepted by the train conductor.. Cheers