Guest Xubuntu 20.04.2 is laggy

[testinguser1411]

I used to use this VDI all the time a while ago on this same system and it ran perfectly, however I've had an hard disk failure and upgraded to an SSD and set it up again, but now it feels a little sluggish, with a small noticeable delay from when I type something to when it shows on the screen, so I think I probably messed up somewhere along the way when I was adding the VDI or maybe I forgot some important setting. It's not egregious, but it's very bothersome when I'm writing code.
I've uploaded the logs, my host is windows 10 and I'm running VM 6.1.16.

[mpack]

Not enough host RAM.

00:00:04.097322 Host RAM: 8070MB (7.8GB) total, 3634MB (3.5GB) available
...
00:00:04.314448 RamSize <integer> = 0x0000000100000000 (4 294 967 296, 4 096 MB, 4.0 GB)
00:00:04.314681 VRamSize <integer> = 0x0000000008000000 (134 217 728, 128 MB)

You should upgrade VirtualBox. Also, you are not using the official Guest Additions. It should not have that "Ubuntu" tag. That should be fixed asap.

00:00:17.022602 VMMDev: Guest Additions information report: Version 6.1.16 r140961 '6.1.16_Ubuntu'

[testinguser1411]

That's really odd, I'm 100% sure I downloaded the guest additions from the official website. Should I uninstall them (somehow) and then install the latest from the website?
I'm updating it, regarding the ram do you mean that I should allocate less ram to the guest?

[mpack]

You don't install the Guest Additions from any website - the correct version came bundled with the software you already installed. Instructions for installing the GAs are in the user manual.

For licensing reasons you do need to download the Extension Pack separately. But (a) that gets installed on the host, not the guest, and (b) you haven't installed the extension pack either, so it doesn't seem that you were referring to that.