iPhone 18 Pro Keeps Saying Incorrect Wi-Fi Password (But It's Correct)

I started having this problem last night. Basically, I was having trouble to reconnect my iPhone 18 Pro to my Wi-Fi network. Suddenly, last night, my iPhone 18 Pro decided that my Wi-Fi password was incorrect, even though I was using the same password for years without any problem. Here is what exactly happened in this order:

My iPhone disconnected from a Wi-Fi connection that my iPhone had been connected to
My iPhone tried to re-connect. My iPhone was not able to connect automatically, like it did all the time
But iPhone did not accept the network password to let me join, even I entered the correct password manually also.

This article explains how I was able to resolve this problem. Are you having the same problem? All iOS devices can have this problem. Randomly, your iPhone 18 Pro or iPhone 18 Pro Max says the Wi-Fi password is incorrect? If you are having the same issue, please follow the steps below to resolve it:

Incorrect Wi-Fi Password

Steps to resolve this problem, please after each step check if you fixed the problem:

First of all, lets make sure that you are entering the password correctly (note that Wi-Fi passwords are case sensitive)
Do you have other devices and are they connecting the same Wi-Fi without any problems?
Make sure that Auto-Join is turned on. Go to Settings > Wi-Fi, tap Edit in the upper-right corner of the screen, tap the More Info button next to your network and turn on Auto-Join.
Weak Wi-Fi signals may cause this. Move closer to your router, does this fix your problem? If it does, then your problem is poor Wi-Fi signals. If your router supports separate frequencies, try joining another frequency—for example, join 5 GHz instead of 2.4 GHz.
Go to Settings and turn Airplane Mode on and off. Wait five seconds between turning Airplane Mode on and off.
Make sure Connectivity Assist is off. Go to Settings > Wi-Fi, then scroll down to Connectivity Assist.
In iOS, tap Settings > Wi-Fi, then tap Edit in the upper-right corner of the screen, tap the More Info button next to your network and tap Forget This Network, tap Forget and then try to reconnect.
Restart everything:
1. Your iPhone. You can shut down your device by going to Settings > General and scroll down and then tap Shut Down, then drag the slider. To turn it back on, press and hold the side button until you see the Apple logo.
2. Restart your router and Modem. Unplug your router (and modem) from its power source. Wait about one minute. And then reconnect by plugging them back into the power source. Some modems have backup batteries. If your modem has batteries, remove these as well. Wi-Fi interference from other connections many cause this problem. Restarting your router will likely fix this.
Update everything:
1. Update your iPhone. You can do so wirelessly by going to Settings > General > Software Update
2. Make sure that your router has the latest software. Check your router’s manual to see how you can update.
If your iPhone can’t join a Wi-Fi network, you should install the latest software updates. Then try again before you decide whether to turn off Private Wi-Fi Address. Go to Settings > Wi-Fi, tap Edit in the upper-right corner of the screen, tap the More Info button next to the network name, tap Private Wi-Fi Address, then tap Off.
If you are still having problems, reset your network settings. Please note that doing so will remove your settings (e.g., your Wi-Fi passwords etc). Simply go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings. Do not worry, you will not lose any data.
Check to see if your router has MAC filtering enabled, turn off MAC filtering (Media Access Control) if it is on. MAC filtering limits the devices. Please note that this is mostly disabled by default. See your router’s manual for more information regarding this. Apple recommends this disabled.