It looks like you have two routers in your network - the BT Home Hub and the TP-Link Archer AX20.
There are several other threads at the moment dealing with similar issues - for example: ARC cant connect to server multiple nat.
The long and the short of it all is that you need to do one of the following:
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Remove one of the routers. If the BT home hub is providing ADSL or VDSL modem features, then the only one you can remove is the TP-link. If you have Full Fibre (FTTP) with a wall mount ONT, then you can probably get rid of the BT router by connecting the TP-link directly to the ONT and then changing it’s settings to use PPPoE using a login name set to “bthomehub@btbroadband.com” and a password set to “BT”.
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If you can’t or don’t want to remove one of the routers, then you will need to either configure the BT home hub in modem only mode (I don’t know whether that’s possible - I suspect not) or set the TP-Link Archer AX20 into Access Point mode or Bridge mode.