Long project loading then cubase freezes

Hello! I’ve got a very annoying problem. When I load some projects they tend to take more and more time to load and finally cubase freezes on a step of mixconsole loading. It says loading kick channel for example and nothing happens. Task manager says cubase.exe not responding. Sometimes it may move futher to next channel like snare but it takes about 5 minutes. Perhaps it will eventually load but I’ve never waited for so long.

My setup:
Intel i7700k 4cores/8threads 16 Gb RAM (2slots) system SSD
files and soundbanks are stored on 1 SSD + 3 HDDs
Windows 10 Pro with last system update
Cubase 10.5.20 (USB eLicenser with latest driver version)
Soundcards: RME fireface 800 (firewire) and RME babyface pro (usb)
Geforce Gtx 660 Ti

It usually happens when I load a rather big project: about 40 audio tracks, 6 fx channels, 8 group tracks and many VST effects in inserts (about 100 I think). But may also occure with loading others. The only thing that helps is rebooting. And that’s a big surprise for me. Safe mode (deactivating thirdparty VST plugins and insturments) also makes it possible to load but I can’t make mixes without my plugins. Also I don’t think that rebooting PC after every project is proper behavior.
Cubase doesn’t crash (so no crash dump files) it just stucks at loading mixconsole. I may get dump file from Win taskmanager but its size is 1.5 Gb.
I tried moving one of such projects to systemSSD. I tried opening in safe mode and saving with other name. I tried closing cubase and opening projects from file explorer. I tried deleting cubase’s profile (C:\Users<Username>\AppData\Roaming\Steinberg\Cubase 10.5_64). Reinstalling Waves Central helped a bit now it loads faster but at some point still freezes.

I’ve searched the forum and the closest thread is here: https://www.steinberg.net/forums/viewtopic.php?p=659563#p659563 posts by In_Stereo
It really looks like system memory is not fully flushed when I close a project. So eventually some ‘cache’ overflows and it freezes. I observed RAM usage via TaskManager and when I close a ptoect it gets to ~165Mb for cubase.exe but reserved memory (not sure about its English name) gets larger with every project that I open and close. I may even not play any audio, just open and close 5-6 projects and get that freeze. As I remember GPU usage for cubase.exe is usually 0% at those moments but not sure it’s important.
It also seemed to have place on Windows 7 with Cubase 10.5.20 and the previous one. I’ve updated OS and reinstalled all programs in hope to get stable performance but it didn’t help.
I tried to create a ticket in MySteinberg but it redirects me to Yamaha company which support system doesn’t have software products option. So little hope for that way.
I wish Martin or other great guys from Steinberg or the forum could help me here. Currently downloaded cubase 9.5 to see if it persists there.

Hey, many Cubase users have the habit of fully closing Cubase in between projects because certain plugins may not clear RAM fully simply by closing a project. Is that what you are doing?
I have found I have best results to fully close Cubse (check Task Manager if not sure) then open Cubase then load a big project, that works for me all the time.

Thanks for assistance, I’ll try a few more times to close Cubase completely and open projects via file explorer. I’ll write if it helps.
Yesterday I noticed Waves plugins taking too much time to appear in inserts: I’ve recorded a video of adding NLS Channel Stereo taking 18 seconds to load. Is that Waves problem?
P.S. I’ve got Waves Central installed to handle plugins and their licenses. As far as I know I can’t use them without that heavy clumsy app.