All pi servers stopped working at same time. How to identify issue?

Hello. I have read all the rules but I am unable to attach any files due to my issue and what ive done to try to fix it. the SD cards have been reformatted already.

I have 4 pi 4's each connected to a ender 3. I have had them running and working with octoprint for close to a year or a little over a year idk. I never had any issues. all connected via Ethernet.

2 days ago I go to update my print que, I open up octopi.local and I get this message. On every single pi
I get this message no matter what device I try to connect with.

This site canโ€™t be reached

Check if there is a typo in octopi2.local.

  • If spelling is correct, [try running Windows Network Diagnostics](javascript:diagnoseErrors()).
    DNS_PROBE_FINISHED_NXDOMAIN

I have tried
resetting my router. resetting my pi's. resetting my pc. I sadly do not have the password to get into the admin panel of my router to see if the pis can be found (I assume they can't) (I can reset if needed my landlord said its fine, its his WIFI we live with him)

I have formatted my sd cards and reinstalled octoprint, I get the same error.

I used a brand new never before opened pi 4b I had leftover from the lot I bought last year, It gave me the same message saying is it a typo it cant be reached.

At this point does this seem like a network issue? and if so what can I do to check this? I am a noob so I do not know much about networking and stuff related.

I guess there is one thing I do remember, the night before I noticed them all stop working. I woke up at like 3am to find the power in my basement living room out (this is where my router and modem are but my pi's/printer are NOT on this same circuit) and the fuze was popped, I reset it and its been fine since. the router and everything work and I can connect to wifi via my phone and tv's. I also have Ethernet on other devices that work so the router does not seem damaged.

im at a loss and I use this as side business having this out and not working is really hard on me. any help or input would be appreciated. I really have zero clue what to do at this point. printing manually is hell I dont want to set a timer evey 3 hours to swap prints when im trying to sleep lol.

any help at all? or I just cant use pis any more I guess?

When you connect an HDMI TV/monitor to a Pi, you should get to see the startup sequence.
When the Pi can establish a WiFi connection, you will get the IP address of that Pi.
If the WiFi does not work, you can try a Ethernet cable connection.

Do your 4 RPi systems have unique hostnames? If not, this is the first place to start. Many routers (the DHCP services they provide) get confused when there are multiple devices with the same hostname.

Search this forum for "change hostname" for instructions.