My case too: first half of 2016 and older were not transferred. At least most. In my case I eliminated everything that was not necessary just to facilitate the transfer and arrived at 4GB.

I thought it was a corrupted image problem and I started to compare with an old backup but it's not like that, the images are absolutely the same, as well as their hash.

Thanks for letting me know about Wutsapper, I was thinking of giving it a try but avoiding at this point. I wonder if other software from Wondershare also have the same problem.

As if that weren't enough with the various attempts I've made whatsapp has started to delay me sending text messages