make sure the version of save is the same as your game before you import
IF you have done that FIRST DELETE your save in the console your importing, then try importing
All versions the same across the board here. Do you mean to delete the save first with the Switch console or delete the save file from SysNAND with HacDiskMount?
I ended up crafting this technique to keep my two systems clean:
Source Switch
1. Update to newest OFW / ACNH
2. Enable Airplane Mode
3. Clone OFW to emuMMC
4. Launch full CFW on emuMMC
5. Make JKSV backup of ACNH
Target Switch
1. Update to newest OFW / ACNH
2. Play game and create dummy save
3. Enable Airplane mode
4. Clone OFW to emuMMC
5. Launch full CFW on emuMMC
6. Restore save from source Switch JKSV backup
7. Play game and save.
8. Mount emuMMC with Hekate and HacDiskMount.
9. Extract save files
10. Mount SysNAND with Hekate (make sure Read-Only is OFF) and HacDiskMount
11. Rename the extracted save files from before to match those on SysNAND.
12. Overwrite the 2 SysNAND files with your newly renamed extracted files.
13. Unmount, poer off console, reboot to OFW
14. Profit.