proposal:

1. try login PSN using your laptop/pc/phone app with the same network.
- is it still having problematic connection?

2. bring your PS4 Pro to a friend's house and try to connect.
- is it having same problem?

3. try login your PS4 with another account (create a different account or use friend's one)
- is it having similar problem?

4. try pulling a LAN cable for connection instead, and don't forget to off your PS4's wifi if you try this.

5. the PSN login which you're using - is it R1/R2/R3? the one that you tried with (3) --> same region as per your original?

6. if you have decent amount of mobile data, why not try hotspot connection - just to try login to PSN?

btw, have you tried other games - i mean, what is your actual connection issue:

1. PSN connectivity intermittent

or

2. PES18 servers connection intermittent

if you try playing other online games, will it face similar issue?