I had no problem till 2018.05 BUILD 20
On my system with SDD drives use to take a couple of seconds to load.
Just timed it - it now takes just under 2 minutes  (1:54)

There were absolutely no changes to the application other than changing some Japanese resources. The update could have no impact to startup time and the cakewalk executable is in fact the same size as the prior build.
Check your VST scan options and ensure its set to automatic rather than manual or scan for failed plugins.

Even on my "slow" laptop it takes only 23 seconds to start CbB!
To achieve this I have set "Manual Scan" and both "Rescan Failed Plug-ins", "Rescan Existing Plug-ins" to OFF. Additionally I have DEactivated "File > Advanced > Show Start Screen", this saved most of the start-up time on my PCs and it is really a unnecessary function IMHO.
 
Chap

I get consistent Startup screen in about 7-9 seconds. 
 
Starting a project with 25 audio trks, and 30+ plugins = 50 seconds. Not bad.
 
I have noticed that the plugins you have that can have an effect on how long it takes to load the project.

Noel Borthwick [Cakewalk]
There were absolutely no changes to the application other than changing some Japanese resources. The update could have no impact to startup time and the cakewalk executable is in fact the same size as the prior build.
Check your VST scan options and ensure its set to automatic rather than manual or scan for failed plugins.

Since Manual Scan would indicate that Cakewalk not take any action with VSTs scan-wise it seems a bit counter-intuitive that that that setting would cause an increase program load time.
 
But regarding my issue - I just did a quick check and load times for either, Automatic or Manual (with no to scan for failed plugs) have one thing in common - they both are significantly longer than I what I was experiencing last week.
Only change on my system since running the previous version of CbB is that I did add a couple of plugins -

• Chromaphone 2 VST3
• Faturator by kiloHearts
• Replika XT by NI and
• Waves StudioRack

and maybe a Windows 10 update...
(but haven't had any issues with previous Win10 updates)
 
Edit: Just ran Sonar Platinum, last release, and it's slower in loading too so looks like something's up on my end.
So apologies for jumping to conclusions.

What about closing projects? Do they take ages to close?