Podcasts app lag and freeze

For the last couple of months my Podcasts app on my iPhone 7+ has been very slow to respond. It starts up very slowly - a white screen and about a minute later my unplayed podcasts appear. But then it takes another minute for those to become active - during this time they wont scroll or respond to touch commands to select or start a podcast. So it sometimes takes 2-3 minutes before i can start listening. Then when I can finally listen, the play/forward/etc buttons may or may not respond crisply.

Now the problem has grown: if i go to another app or stop using my iPhone, the Podcasts interface will occasionally freeze, either on a white screen with a header of Unplayed Episodes or with the full podcast list showing but not scrollable or touch-responsive.

I'm currently on IOS 10.3.2. I typically have a couple hundred podcasts on my phone, so I reduced this down to one podcast, but that didnt improve the lag/freeze. I also tried a reset, and then went further to wipe it all back to factory settings and restored from backup without any success. Note these problems, so far, do not happen with the Music app. Nor, for that matter, in any other iOS app.

This is perplexing because after the early buggy days when the Podcasts app separated from the Music app a few years back, and aside from some subscription issues, playback had been relatively problem-free for me. Has anyone else encountered this issue? Are there any fixes you can recommend?

thanks

guang