Suica card issue

Just returned from a 10 day trip to Japan (8/25/19). During the trip we found that our (3 cards) Tokyo purchased Suica cards did not work in Osaka. Shown the cards to the attendant at the gate in Shin-Osaka station and he made a sign that they dont work there. Also upon the return to Tokyo it did not work again till the Tokyo station gate attendant did something to them. Does anyone know why this happened since the Suica card is suppose to work in both cities? Thanks!

How did you use the Suica cards just before that happening?
Are those two gates (of Shin-Osaka Sta. and of Tokyo Sta.)
both Shinkansen gates?

Maybe:
Each of you touched the card at one station
to enter the railway network,
but did not touch the card at another station
to exit the network.

In that case,
your adjustment is not yet completed;
so, when you later touch the card at any entrance gate,
the gate machine rejects the card and halts you,
urging you to use the manned passage.

Sounds like you swiped on somehwere in Tokyo and didnt swipe off. Locking the card into that trip only.

You will have failed to exit a train system/company properly. If it was the Tokyo subway, only a Tokyo subway attendant could clear the error. If it was a JR station, that could be fixed in Osaka at JR. But if you had an error on the Osaka subway, no one in Tokyo would be able to fix that until you return to Osaka. One of the "features" is that only the company where the error occurred can fix it.

It is important to take note if the ticket gates correctly register each use. Nothing wrong with the cards. The cards would still work at combini/vending machines.

Thank you all! Now it is clear why. Lesson learned.