Hello friends, I have a question?
What is the DSL profile section for?
I asked my ISP for fast mode but I can not see the word FAST anywhere.
If in other D-Link modems, there is a section that announces the status of the line. Is the DSL profile section for line mode display?
As for fastpath (what you call fast mode), if Interleaving is not shown on Openwrt the only other way is to use software called DSLstats, i personally use this myself to monitor my line have done since i had ADSL1 and continue to do so since moving to VDSL2.
All you need is access to telnet for that software to work. It will then show interleave depth, if it shows 1 your on fastpath, any other value means your on interleave.
Due to your SATN and LATN being so high i would place my bet that your on Interleave.
I would guess this is for the profile/bandplan in use on VDSL2 links?
Look at the "Latency" row, older OpenWrt versions did replace the number with the word "fast' when the value was below a certain threshold (the numerical value of which I forgot). But 19.5/18.25 does not look like "fast-path" to me but rather that interleaving is used. Which probably is a good thing given that you ask for help with line stability. I think there somewhere is a setting in the network tab by which you can configure your modem for a higher SNR for the download direction, which , if it works, tends to result in higher robustness (but only if your problems are related to issues in the download direction, obviously).
That is not going to help, since DSLstats works exclusively with Broadcom dsl modems, while the OP's BT HomeHub 5A is based on Lantiq's xrx200 dsl SoC (Lantiq is the only dsl SoC with OpenWrt support).