Have you attempted with the version 1.85 fw linked earlier (page 8)? Not sure it will make a difference, but it is worth a shot and flashed to mine fine.
Weird that saving didn't work, most Pokemon bootlegs do tend to include saving save the real crap ones.
In fact my only Pokemon bootlegs that don't save are those with dead batteries.
https://www.aliexpress.com/item/1005005586506154.html (Golden Sun 2 The Lost Age, Gold Sun 1 are Batteryless patched)
this is a 32MB cart with Flash save as Mother 3 uses Flash save also, you will not need to SRAM Patch/Batterless Patch...
Saving works great now, but Metroid Zero Mission would tell me it was corrupt before patching with this patcher. This cart seems to use NOR flash in lieu of the SRAM to save. There does seem to be a SRAM chip on further inspection (EM611FV16) but...
This bootleg Pokemon Sapphire cart contains a 16MB/128Mb JS28F128 Intel chip (as of purchase within the last two weeks) and I was able to write Metroid Zero Mission without issue using this tool. Saving did not initially work natively, as...
I used to have a DS Link, it never really worked that well and game/homebrew compatibility was very poor. I would assume it is fairly uncommon since I can't even find anything about it anymore. It was one of the first Slot 1 carts for DS.