The security patches dated the 5th of every months are for the Google released devices (Pixel and Nexus). All other OEMs will released security patches with the date of the 1st of every month.
Don't expect 2 August updates. You will only get the one dated August 1st.
I haven't gotten the July update on my TA 1045 yet. So, i'm not sure i'll even get the August update. I'm very disappointed with Nokia.
I'm guessing your either on A or B firmware. Considering the Nokia 6 already has August update they're probably having issues. With all the new models likely over the intended support period of this phone, it doesn't look good. The August update though may include the security update, firmware, and a new Android build (hopefully branch 43, the latest Oreo branch), and these issues are resolved. If not, and these issues continue, the phone is a dud model but I doubt they'd admit that. At this rate the Nokia 6 will get Android 9 and access to the beta (if they do one) before this phone.