My dream .com domain name is squatted by somebody in Korea owning 10.000s of domains. One year they forgot to pay their registration, 'whois' printed 'overdue' (can't remember the exact words). I tried to register, backorder, everything. Nothing worked sadly.
I created an app with that name, unfortunately the domain was already in possession of a turkish PV company that went out of business. I noticed that the domain will lapse in a couple of months, so I used Snapnames (if I remember correctly) to set up a domain drop catching service.
Meanwhile, I got an email from someone representing the Turkish company who independently asked me if I wanted to buy the domain for a couple of thousand USD. I was getting nervous, but decided to go radiosilent on that matter.
Well it worked, they must have thought I'm out of business as well, or whatever. A couple weeks later the domain dropped and got picked up by Snapnames in my name.
In my case, I failed to notice the renewal notice and only realized that I missed it once the domains stopped resolving. The grace period let me avoid losing them.
I've been working on going from calendar reminders to, at least, semi-automating checking a list of expiration dates, and then checking regularly. I'm still making mistakes, I'm just trying to avoid repeating them and instead make exciting new mistakes.
For about 3 months, I checked the whois weekly. Some company was holding it. I never visited the domain in any way, to help the domain feel dead to their analytics.
Then one day, the whois result matched what you get from whois-ing a bunch of random letters with .com. It was finally released. I registered it from a company like namesilo or porkbun for the standard .com price.