SUMMARY
Dolphin breadcrumbs in location bar are inconsistent.

STEPS TO REPRODUCE
1. In Dolphin, in the Home folder, create a folder 'test1' and go into it. 
The breadcrumbs show: 
> Home > test1

2. Go back to Home folder & go into the Downloads folder.
The breadcrumbs show:
> Downloads

3. Still within the Downloads folder, create subfolder 'test2' & go into it. 
The breadcrumbs show:
> Downloads > test2

4. In Dolphin's left panel, click on any folder or a recently used folder that auto-populates, e.g. "LastFolder" shows on the left side (real directory is /home/zippy/500gb_b/2ND_LAST/LastFolder)
The breadcrumbs show:
> LastFolder

5. In Dolphin go back to Home & then navigate through to the folder one level above 'LastFolder', i.e. so far as 2ND_LAST.
The breadcrumbs show:
> Home > 500gb_b > 2ND_LAST

6. Go one step further than #5 and go into "LastFolder" folder. 
The breadcrumbs show:
> LastFolder

OBSERVED RESULT:
The breadcrumb convention has changed between 5 & 6. Number 6 dropped all the higher level folders.
"> Home" is missing from 2 & 3.

EXPECTED RESULT:
1. > Home > test1
2. > Home > Downloads
3. > Home > Downloads > test2
4. > Home > 500gb > 2ND_LAST > Lastfolder
5. > Home > 500gb > 2ND_LAST
6. > Home > 500gb > 2ND_LAST > Lastfolder

NOTES:
Having the breadcumbs consistently stem from 'Home' and show each folder branch to the folder you're in is a useful navigation tool. 
Configuring Dolphin to 'Show full path inside location bar' adds the extra "/ > Home > USERNAME > " hence isn't quite a solution as it doesn't follow the nicer convention above ("Home" > Foldername...).

SOFTWARE/OS VERSIONS
Operating System: Debian GNU/Linux 11
KDE Plasma Version: 5.20.5
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2
Kernel Version: 5.10.0-8-amd64
OS Type: 64-bit
Processors: 4 × Intel® Core™ i5-4570 CPU @ 3.20GHz
Memory: 7.7 GiB of RAM
Graphics Processor: GeForce GTX 750 Ti/PCIe/SSE2