All Should Be Official, i also have x2 bt home hub 5a and TP-Link WR2543ND Both Running 19.07.9, just using This D-Link To Test With, Its On 17.x as 19.x wouldn't save config after reboot (low storage device)
It would be wise to use a newer device with the ability to run a modern version of OpenWrt. LEDE has been EOL for many years now, and is unsupported and has many actively exploited/exploitable vulnerabilities, and really shouldn't be used on the internet anymore.
While we're talking about that... 19.07.10 was just released and that is the final release of the 19.07 series releases and it is officially EOL. It is no longer supported in terms of updates/bug-fixes/security patches (although obviously forum support continues). Consider upgrading your other devices to 21.02 if possible.
I'm sure people here will still give you a best-effort attempt to help resolve your issue, but given the age of LEDE as an OS, it is possible there are nuances that people will not remember.
Will Update One Hub 5a (128/218) to 19.10 & The Other To 20.03, i did try both (i think) 20.01 & 20.02 And they resulted in lower wifi performance, i think the tp link will be stuck on 19.x, not sure if i tried 20.x, think maybe decided to roll back too on there (8/64 device) , Yhe the dlink i bought in 2014, came with DDWRT with a 2013 build on it, used that for a few years, Will see on newer openwrt & see
so results with testing, 20.x on TP Link, 10 Mbps Slower Download Throughput vs 19.x, simmilar with BT Hubs But Not As Bad, Will Have To Try 19 again on d-link but not hopeful here, ill probably stick with 19.10 for now