I've had an issue with the game crashing and freezing since the second to last update, so it's not just you. Since the last update I've still had freezing, lagging and complete shut down issues. I hope the downtime the 26th will fix this. Nintendo even put out a notice saying they are trying to fox the game 'frequently crashing'. They legit used the word frequently.
Edit: another player I know irl has these issues frequently as well, I think she may have had some today. I know she def had some serious issues yesterday and the day before. We both use old phones.