Adding nft plots created with madmax to ubuntu chia installation

Hi, I have a raspberry pi 4 setup with ubuntu 20, running chia 1.2. I have several solo plots working fine. I have joined ecochia pool recently. Now I have created some nft plots on a separate windows pc using madmax and using the -c parameter.
The question is, how to add these nft plots to my ubuntu setup by command line? no GUI on ubuntu.
I tried “chia plots add” to add the directory with new nft plots, but when I run “chia plots check” I get this error on nft plots. Any ideas how should I do this?
Thanks…

Failed to open file
badbit or failbit after reading size 4 at position 107543139038 Traceback (most recent call last):
File “/usr/chia-blockchain/chia/plotting/plot_tools.py”, line 189, in process_file
prover = DiskProver(str(filename))
RuntimeError: badbit or failbit after reading size 4 at position 107543139038

The file is corrupted. How did you copy it on the device? Please check the filesize of all that files. Are they 100GB or larger?

Thanks. I use hdd to transfer files. I did it lot s of times for solo plots and never get this error. Yes size is ok.
So, do you mean that the “chia plots add” command is correct and it should works also for nft plots?