Resolve doesn't remember proxies

Hi there, everyone!
I have a problem with proxies and it would be awesome if anyone could help me!
So, I have a pretty big project for a music video. About 20 video tracks, many fast cuts and some fusion clips. Everything 4K.

The cutting process was nearly impossible, even with half or quarter resolution, so I made proxies for everything (half resolution, DNxHR SQ). And BOOM! Everything works instantly like a charm.
So I cut a for a few hours and saved multiple times.

The next day I open the project again and everything is working as crappy as it did before using the proxies. But the proxy-files are still in place on the harddrive!

Is it possible that Resolve “forgot” about the proxies? (“Use Proxy Media if available” is checked)
Can I test this somehow? When I uncheck “Use Proxy Medie if available”, the resolution doesn’t seem to shrink, albeit I generated the proxy media with half resolution.
I’m using the Resolve Studio Version 17.1.
Thanks a lot!

Specs:
Intel Core i7 6700, 3,4GHz
GTX1070 Strix OC
16GB Ram
Windows 10
Everything is on a HDD, because SSD isn’t big enough.

In the Media pool, you can right click on the properties panel and enable "Proxy" and "Proxy media path" Might help narrow down if the proxies are being used, or at least is Resolve is seeing where they're located.

Hey Ryan,
thank you very much for your answer!
I wasn't able to find a "properties panel" in the media pool (Edit Tab, upper left corner > media pool, right?), but I right clicked on media in my timeline, and it said the linked media is the proxy, so this seems about right. But I still don't understand why the cut page is that slow again, even with the linked proxies. Anyway, thank you very much!

UPDATE:
It seems that my render cache has been the problem.
I deleted the complete cache, then set the render cache to none and back to smart.

I thought Resolve deletes the render cache by itself after restarts, so I didn't think of that solution.