Seems that you need a new SD card.
If you have a running update period, get a new card, insert into PC and install software and car data via the PC suite.
I use a Transcend Class 10 UHS1 card with 32 GB.
Here in the forum you will find a lot of posts about new SD card procedures.
And, you can create as many cards as you like.
I have two, one is always updated via the DS708 the other via the PC suite as backup. Never had problems this way.