Thank you for your opinion, witcher_sense, but it's not that.
I have the Bitcoin Segwit wallet disabled (by me) before I made that transaction from 2 days ago. And this wallet was added recently to Jaxx, through an app update. The old BTC funds I had were inside the Bitcoin wallet. And those funds were shown in the wallet, on Jaxx's main screen and also on the upper part of main screen, where you can see the cumulative funds of all wallets. I had obtained the old funds before Jaxx started to support Bitcoin Segwit.
And the new funds were bought also using the classic Bitcoin wallet, not the Segwit one (as this one was disabled).
So, practically, now I see the old funds (on main screen) and not the new funds I bought recently. But if I try to send funds, if I select in that screen Max (to use the maximum amount which can be used) it shows me that I can sent all the funds I am supposed to have (the old ones and the ones I bought recently).
So it's practically a UI error, as the new funds are not shown in main screen, added to the existent ones. I hope I explained more clear now.
I assume you have checked the transaction on a blockchain explorer and it's confirmed to have been received in the correct address.
Yes, indeed. The transfer was successful, as I wrote in OP. Besides, I can also send all the funds (old ones + new ones). It's just the total amount is not shown on app's main screen.
Is there a way to delete your Bitcoin wallet safely and re-add it?
Does Jaxx have a resync feature or a way to delete the cache to fix what the UI is displaying?
It has but, given the curious situation, I am afraid of doing that, in order to not lose all the funds I have

But the best option would be to abandon it entirely, create a new Bitcoin wallet with a more reliable software, and transfer all your Bitcoin to it.
I also have another Bitcoin wallet, not only Jaxx... But I would not want to lose these funds I have there...