I have experienced that too. At least Google maps offers the possibility of saving 'offline maps' on which still the phone GPS can still route you, but without the alerts and traffic data.
I guess I was lucky that the best route to my undefined address brought me to within 600' of my house (and on the proper road to get there). In my case, we didn't show up on the maps because we were the first residents in a new community. I did submit a correction to Garmin. It was maybe a year before we showed up properly on Garmin, but I have no way of knowing whether my 'correction' had any impact. It could have just been the normal course of growing the maps over time as new roads emerge.
I just had the same problem with my 32 G drive that used to work for updates. I should have checked here first. I guess I'll stick to Waze until they fix this.
Then welcome to the permanent world of Waze. I don't think this is a high-priority problem for Honda/Garmin. If word about the requirement for a 16 GB thumb drive gets out, they're not worried about it affecting future Clarity sales.
True - But if word gets out that they make buggy software (I cleaned up my words) it may impact public perception of their competence.
From personal experience it's like talking to one of those Chatty Cathy dolls. Same useless response over and over. I bought a new Garmin for our trip to Ireland and it was often useless here in Las Vegas. Wrong end location even with the correct address given. Facing the wrong direction at intersections. Sent down a street half a mile and a U-turn to get to a mall right across the street with an intersection into it right in front of me. Our 15 year old Garmin was accurate. All explained as "normal" until the unit learns our area. BS.
They said I need a 16 GB USB drive (although the previous update worked with my 32 GB stick.) Even though I use Waze most of the time, I bought a 16 GB stick just to keep the car current. It worked. BUT, I don't think I would knowingly buy anything from Garmin in the future.
It used to work with larger sticks. When was the last time you tried with the 256? Did you set up a smaller partition?
Reformatted a 32GB with a 16GB partition because I was short on time. Didn't want to go through it multiple times if it didn't like the 32GB. Edit: Worked flawlessly except that it said it failed. I went into settings. It installed.
I've also used a 32GB for map updates and now getting the "not enough space" error. Almost bought a 16GB stick that I don't need because official support states: The Honda Navigation System update requires a 16GB USB flash drive. Using a USB flash drive smaller or larger than 16GB can cause the map update process to be unsuccessful. The following error message may display: "There is not enough space on the device to install the map update from USB storage device." Check the /garmin/asr folder for old map update files. Delete the old files. Keep the (5?) new files from the latest update. TADA! Source: https://www.piloteers.org/threads/navigation-not-enough-storage-for-new-map.170878/post-1753399