Firmware Update Problems

This is on a 6TB WD MyCloud single disc that I purchased in January 2016 to backup my iMac with Time Machine.
Last week I discovered that my phone wasn’t backing up to this any longer so checked for firmware updates - none available. I’ve sorted this out but in the process had to reboot the NAS to get the phone to connect again. It then found a firmware update so I installed it.
After the update was completed Time Machine threw up an error saying that the username and/or password were invalid for the backup disc. The only way I knew of sorting this was to re-select the device from Time machine which, as on 2 or 3 previous occasions, caused it to ignore he existing backup and create a new one. Left it running overnight. Checked it next day and there is no sign of the new backup and Time Machine is now showing details of the previous backup. After nearly 24 hours there is no sign of the backup it was creating.
Did a quick and then a full diagnostic test which again ran overnight, spending a long time at 90%, but was eventually successful.
Got round to trying another backup
19:02 Preparing Backup: 5.02 TB available of 5.83
22:25 Backing up 316.4 MB of 14.15 GB
06:00 Backing up 691.4 MB of 14.15 GB 24/05/20
08:20 Backing up 910.4 MB of 14:15 GB
10:00 998 MB
17:45 1.12 GB
Rather slow.
Also I was getting “The operation can’t be completed because the original item for “TimeMachineBackup” can’t be found” when using Finder to show the share details. I also got this when trying to connect to a Linux PC share via Samba but got around this by using Cmd-K in Finder to bring up a share dialogue and connecting from this. 1.6GB copied from Linux to iMac in 20 seconds, so network ok.

Questions

  1. I am guessing that auto updates have caused the previous occurrences of the username and password issues and me reselecting the TimeMachine disc. Is there a way to reconnect to the existing share and avoid losing the previous backup?
  2. I have read that slow backups and the “operation can’t be completed” error can be related to the wrong protocol being used. Is there a way to check this before applying the fix?
  3. If the two issues aren’t related, is there a way to use Cmd-K to connect to Time Machine without having to create a new backup?

Many thanks
Paul

I discovered that my version 1 MyCloud is still supported by accidentally coming across the firmware release notes. It also states that support for SMB-3 was released in 04.05.00-320 dated 04-12-2017 and that SMB is the new default protocol. As far as I can tell, the only way to implement this manually is to use the “tmutil setdestination” command as in Answer ID 21360, viz
https://support-en.wd.com/app/answers/detail/a_id/21360
According to “man tmutil” from a Terminal session this will replace the existing connection from TimeMachine with one that uses the IP address and not the WDMyCloud device. This will also remove access to the existing backup I presume.

These are the answers to the above questions that I have found so far:-

  1. Existing connection information can be found by using “tmutil destination info” which as well as giving the url and protocol (smb or afp in this case), also gives the unique ID for the connection.

Questions 1 and 3 are really concatenated into one question. I have therefore raised a call with support (200603-004127) asking how to modify the connection to SMB without losing access to the existing backup.