I have no idea what you mean.
Which SIP where and what?
What line is on 5060?
PSTN SIP isn’t a thing. PSTN is an analog channel that comes into your device on a two-wire cord - SIP is an Internet Protocol that runs on Ethernet.
Where are the lines showing “Registered”?
I’m so confused right now that I can’t figure out what you are trying to do anymore.
Can we simplify this for a minute? Your SPA is connected to an analog phone line. It has at least one Ethernet connection to your FreePBX server. This connection should be available full time.
On the SPA, you connect to the SIP port on the FreePBX Server. Note that both devices have a listening port number and both are likely to be 5060 (since that’s the well-known port address for SIP).
The log files (/var/log/asterisk/full) will tell you what is and isn’t working. I have yet to see those logs, so I’m still not convinced that what you think is happening is what is actually happening. I think your next troubleshooting step will need to be reviewing those logs and trying to figure out what is not working. I’ve already said that your SPA configuration looks wrong, but without knowing what the failures are on the PBX there’s no way of knowing.