The 17a profile is the particular frequency mapping of the Openreach VDSL2 service and we all have that.
The IP Profile
is set by BT Wholesale, to limit the true data speed sent to the DSLAM, to avoid packet loss. Plusnet get an update three or four times a day listing any changed IP Profiles, and set their Current line speed
a fraction below it.
Occasionally that update procedure fails. In cases such as yours what has normally happened is that for some reason you had a low sync which dropped the IP Profile and CLS. When you later had a re-sync which raised the IP Profile, the update to Plusnet failed.
As advised, you can contact Plusnet support through Chat and get it manually adjusted. A less reliable method that does usually work is to disconnect the modem for tem minutes or so, then reconnect. This will probably cause a change of IP Profile, and when the Plusnet copy later takes place it is likely to pick it up and correct the CLS.
Reconnecting at this time of day is likely to give you a lower connection speed and therefore IP Profile than doing so well inside daylight hours.
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