Repacked modified super.img - can't see new files

I got a Chinese phone with an MTK6761 SoC, running Android 13 (has the virtual A/B partition and DM-verity/AVB enabled). I managed to unlock the bootloader and root it through Magisk and MTKClient tool running on Manjaro Linux. So far the only "issue" with that is that as I have seccfg modified, I have the annoying message at boot stating that the partitions are corrupted (because of dm-verity). In that regard, I tried disabling dm-verity through the usual methods with no luck. The problem that I am facing is as follows: I am attempting to modify the bootanimation file, which is inside the "product" virtual partition. I found that it is inside super.bin, so I unpacked it using the lpunpack commandline application with the command:

lpunpack super.bin ./Images`

Then, I found there was an image, product_a.img which has the bootanimation.zip, so I increased the allocated size by 10 MB with the following commands:

e2fsck -f product_a.img

fallocate -l 2275078144 product_a.img

resize2fs product_a.img 555439

Then, I mounted it to a folder named "product" with the following command:

sudo mount -t ext4 -o loop,rw product_a.img product

To access and modify its content I used Thunar Root and replaced the bootanimation file with my custom file. Then I unmounted the file using sudo umount product and repacked everything with the following command:

lpmake 
	--super-name super 
	--metadata-size 65536 
	--metadata-slots 2 
	--device super:5368709120 
	--group main:4504506368 
	-p "product_a:none:2275078144:main" -i "product_a=./product_a.img" 
	-p "product_b:none:0:main" -i "product_b=./product_b.img" 
	-p "system_a:none:1678229504:main" -i "system_a=./system_a.img" 
	-p "system_b:none:139591680:main" -i "system_b=./system_b.img" 
	-p "vendor_b:none:0:main" -i "vendor_b=./vendor_b.img" 
	-p "vendor_a:none:411607040:main" -i "vendor_a=./vendor_a.img" 
	-virtual-ab 
	--output ./super.img

I must say that I had to place vendor_b before vendor_a because it being a 0 byte partition made **lpmake** complain if it was the last partition. To get the actual size of each partition I used the result of "stat" command for each, and I used a metadata-size of 65536 as it was "recommended" online. Lastly, I flashed it to the phone through MTKClient:

python mtk w super super.img

The partition was written successfully and the device started correctly but I could not see any changes. So I dumped once again the super image from the phone, and I verified the changes were actually applied to the ROM, and that is when I got really confused. I also tried removing files and adding files to the partition, only to find that the device do not see the changes but they seem to be there when I dump it back tu my PC. I would really appreciate if someone could help me figure out what I am doing wrong.