I'm running Libreelec 12.02. I've had a problem since many iterations ago with connecting to it through wifi. Sometimes it works, other times I get "time out" errors. And I'm not changing anything on the raspi/librelec system, not changing anything on my router, and not changing anything on my computer. Sometimes I can access it without an issue, other times I can not.
I use Pop OS (an Ubunutu fork) on my computer. If I open up my GUI files, under Other Locations, two things will show up: LIBREELEC & Libreelec. The lowercase one I can always access and seems to be the SD card in my Raspi with Libreelec on it. The upppercase one seems to be the whole system, along with the harddrives. Typically, all I have to do is click LIBREELEC, it'll open up the main file system, and then click into the folders for whatever external hard drive I want to access to manage my media collection. As stated above, sometimes this works, other times it doesn't. I assume this is SMB, but in case it isn't, I have also tried directly connecting with smb://IP_GOES_HERE and have the same issues.
When clicking LIBREELEC, I get: "Trying to open Libreelec.local". This is normal. However, when it doesn't work (randomly), I get the following error message: Unable to access location: Failed to retrieve share list from server: Connection timed out.
I do have Samba enabled. It does work a lot of the time. But then there's blocks of time where it stops working for days, and eventually it works again. I don't understand why this is happening or how to fix it.