Starting Libre Office on 6.7.1 from the toolbar icon presents a choice screen in a central window, with the white options area surrounded by pale blue shaded background. In my case, at the left and right sides of this blue background are two strips which are not filled in, but just grab the background image for the area at the time, before LO is started. Having just used the live USB on a desktop monitor for the first time, where the problem did not occur, I think I may have found a reason for this. When opening LO, LXDE seems to use a default window shape roughly conforming to the aspect ratio of the display. The desktop monitor is a 4x3 display, all my other units are 16x9 or 16x10, the area missed out by the background paint is the extra space in the widescreen ratio.
DELL PowerEdge R630 8SFF Server 2x E5-2680v4 2.4GHz =28 Cores 128GB H730 4xRJ45
$339.00
Dell Poweredge R630 Server 2x E5-2620 V4 =16 Cores | S130 | 32GB RAM | 2x trays
$171.99
Dell PowerEdge R630 Server 2x E5-2680 V4 = 28 Cores S130 32GB RAM NEW 480GB SSD
$256.99
DELL PowerEdge R730 Server 2x E5-2680v3 2.5GHz =24 Cores 32GB H730 4xRJ45
$247.00
Dell PowerEdge R630 Server 2x E5-2640v3 2.60Ghz 16-Core 64GB H330
$182.65
HP ProLiant DL360 G9 Server 2x E5-2690v3 2.60Ghz 24-Core 256GB P440ar
$302.90
Lenovo ThinkServer TS140 Xeon E3-1225v3 3.20GHz 16GB RAM Tower Server Needs HDD
$99.99
Cisco UCS C240 M4 2U Server w/ 2x E5-2680v4, NO RAM
$39.99
Dell PowerEdge R720 2U Server 2x Xeon E5-2670 2.60GHz 256GB RAM NO HDD NO OS
$219.99
1U BareMetal pfsense opnsense Router Firewall DNS Server 6x 10GB Ethernet Ports
$149.00