Thank you for that.
Can you remember what brands of ammo you used?
Just about any European 9x19 will work well in a P08.
P38s can have issues with hotter ammo. I've had slide covers and extractors come off more than one of them, when using the black tip surplus ammo that used to be available at very cheap prices back in the day.
That same ammo broke the toggle mechanism on a lovely 1923 Commercial P08 as well. I also saw an Inglis P35 with a bulged barrel from that stuff. It's easily recognizable, steel case with black bullets.
There used to be a lot of discussions on this back in the 50s/60s/70s, when all sorts of surplus ammo was available. Shooters were complaining that North American made 9x19 wouldn't cycle their P38/P08/P35 pistols. If they didn't know what they were looking at, they were often encouraged by many articles in various firearms magazines of the day, to avoid surplus 9x19.
There wasn't a lot of European 9x19 available in Canada or most of the US, so a lot of us handloaded, often after nasty experiences, such as those mentioned above.
There was a common consent that 124grn ammo should be loaded to at least 1200fps to properly function in Lugers (P08), P35s, P38s. Some folks loaded them hotter. Most US ammunition loads the 124 to just over 1100fps.
Norma loads to about 1200fps as does Selior and Belot. I've used a lot of both and they function well in any pistol I've used them in.
P08s/P38s and P35 pistols were designed to function with 124 grain fmj ammunition. Some will handle the lighter 115 grain loads without issue. Especially those that have a bit of wear. If you have a very tight pistol, you may want to stick with 124 grain bullets.
Tradex presently has Centaure 9x19, which I believe is made in Quebec, for sale at $15 per box.
I haven't used or seen that stuff in shootable quantities for a few decades. No great loss.