That is curious, very curious. I'm not trying to be condescending, but are you sure you're looking at OpenWrt (192.168.1.1) and not at a a cached version of the old web interface (192.168.0.1)?
Not trying to say it's the issue, or a solution, but just to drive this point home: OpenWrt's web interface doesn't even use the same address as the D-Link one. How do you expect to get the new web interface if you still call up the wrong address?
Also, did you reset your local ethernet interface to DHCP? You would have had to configure it at 192.168.0.(not 1)/24 to reach the D-Link emergency flash facility, which is the wrong subnet for default OpenWrt.
As far as I remember that's just a simple time-based JavaScript counter that has no way of knowing if the flashing process actually was successful. It just makes sure you wait for x minutes before rebooting.
I have one or two D-Link DIR-505s that are actually slated for a 19.07 upgrade, I can try it on one of mine ... but not within the next few hours.
I can also log into the router with the original D-link FW....makes it unlikely for me that the d-link FW is not there anymore.
Also I realized that flashing the OEM FW does not bring the new FW!
In the meantime, I found that openwrt can be installed by using the FW upgrade mechanism in the standard web interface (i.e. not the rescue web page), exactly the same way as described for upgrading the firmware in the manual.
Somewhat scary, that the rescue path does not work, but as long as nothing goes wrong it seems to work....
@takimata: Do you know if your devices reboot automatically after the FW update using the rescue web page or did you have to do a manual (power-on-) reset on the DIR-505 ?
Just to make sure, I did it on both of my DIR-505s, without any issues.
They do. As mentioned, the percentage counter on the "flashing now" page is a simple JavaScript timer of 120 seconds. Around 67% in, after roughly 90 seconds, the DIR-505 resets and boots to OpenWrt, which needs another minute or so to set up for the first time until the LED goes solid green. After changing the ethernet interface to 192.168.1.2 I can confirm via SSH that the DIR-505 is indeed running 19.07.0 now.
I don't know how to help with your problem because I simply cannot reproduce it. Sorry.
curl http://192.168.0.1/cgi/index -F files=@openwrt-ath79-tiny-dlink_dir-615-e4-squashfs-factory.bin works in Windows 10 but not on Debian Linux 10
PaulFertser reported on IRC, that he saw too many TCP retries on an old D-Link device, that progress was too low. This does not seem to be the case here, here is a wireshark log http://scw.bokomoko.de/~rd/dir-505-wireshark.pcapng