I'm wondering if anyone else is experiencing these problems?
Sporadically (sometimes we have this error, sometimes it works), we are unable to access the APEX environment or the Database Actions environment for our Autonomous Databases.
For example, for our DEV database - I got the error pop-up multiple times, and then it just started working normally. For the TEST database that we have just created - we have not yet been able to connect to Database Actions or APEX. Same error every time...

The error text is as follows:
Database actions uses a private IP address that is only accessible from a Compute instance running with the virtual cloud network (VCN) used by the Autonomous Database. Copy and paste the following access URL into a browser that is running on a Compute instance in the VCN.