Connecting via AMS or CDG?

I've gone thru both on a connecting flight to Lisbon and had no issues. But between the two, I prefer AMS.

I'm going to assume your flights are on one ticket. If you miss the connection due to the 1st flight being delayed, then they would put you on the next flight with open seats. So something you might check is how many flights will be between CDG or AMS to Lisbon for that day in case you do miss the connection. You don't want to be on the last flight of the day and be stuck to the next morning.

I think either would be ok. Have done both with no issues. It might be worth looking at the terminal map to see where your airlines land and depart from. Sometimes you can tell if they use the same terminal or if they are different and would require taking a bus/train within the airport which would take more time. It's not foolproof as gate assignments are always determined the day of but it is a good guess.

I'm a little hesitant regarding CDG because there are so many French labor strikes. I was almost stranded in France pre-COVID.
You could check your flights on FlightAware for their dependability and on- time stats.

Good luck!

I don't ever connect through CDG since I live here, but from everything I hear about connections, I would pick AMS.

I really haven't had a bad experience connecting thru either. I've always heard, if you have a choice between AMS or CDG pick AMS. So, I do, unless I have to pay more.