VDSL on Fritzbox 7362SL

I'd at least keep the VDSL line unconnected for ~15 minutes, that might already help sorting things out.

Didn't make any difference:

{
	"api_version": "4.17.18.6",
	"firmware_version": "5.9.1.4.0.7",
	"chipset": "Lantiq-VRX200",
	"driver_version": "1.5.17.6",
	"state": "Showtime with TC-Layer sync",
	"state_num": 7,
	"up": true,
	"uptime": 740,
	"atu_c": {
		"vendor_id": [
			181,
			0,
			66,
			68,
			67,
			77,
			194,
			127
		],
		"vendor": "Broadcom 194.127",
		"system_vendor_id": [
			181,
			0,
			66,
			68,
			67,
			77,
			0,
			0
		],
		"system_vendor": "Broadcom",
		"version": [
			118,
			49,
			50,
			46,
			48,
			52,
			46,
			49,
			50,
			55,
			32,
			32,
			32,
			32,
			32,
			0
		],
		"serial": [
			101,
			113,
			32,
			110,
			114,
			32,
			112,
			111,
			114,
			116,
			58,
			50,
			50,
			32,
			32,
			111,
			101,
			109,
			105,
			100,
			32,
			115,
			111,
			102,
			116,
			119,
			97,
			114,
			101,
			114,
			101,
			118
		]
	},
	"power_state": "L0 - Synchronized",
	"power_state_num": 0,
	"xtse": [
		0,
		0,
		0,
		0,
		0,
		0,
		0,
		2
	],
	"annex": "B",
	"standard": "G.993.2",
	"profile": "17a",
	"mode": "G.993.2 (VDSL2, Profile 17a)",
	"upstream": {
		"vector": false,
		"trellis": true,
		"bitswap": false,
		"retx": false,
		"virtual_noise": false,
		"interleave_delay": 12000,
		"data_rate": 1577000,
		"latn": 3.000000,
		"satn": 3.000000,
		"snr": 9.600000,
		"actps": -90.100000,
		"actatp": 2.700000,
		"attndr": 1716000
	},
	"downstream": {
		"vector": false,
		"trellis": true,
		"bitswap": true,
		"retx": true,
		"virtual_noise": false,
		"interleave_delay": 640,
		"data_rate": 21711000,
		"latn": 5.100000,
		"satn": 5.100000,
		"snr": 6.400000,
		"actps": -90.100000,
		"actatp": 12.800000,
		"attndr": 22118400
	},
	"errors": {
		"near": {
			"es": 0,
			"ses": 0,
			"loss": 2,
			"uas": 439752,
			"lofs": 0,
			"fecs": 0,
			"hec": 0,
			"ibe": 0,
			"crc_p": 1,
			"crcp_p": 0,
			"cv_p": 0,
			"cvp_p": 0,
			"rx_corrupted": 6823,
			"rx_uncorrected_protected": 6798,
			"rx_retransmitted": 0,
			"rx_corrected": 25,
			"tx_retransmitted": 0
		},
		"far": {
			"es": 19,
			"ses": 6,
			"loss": 0,
			"uas": 439752,
			"lofs": 0,
			"fecs": 6462,
			"hec": 0,
			"ibe": 0,
			"crc_p": 0,
			"crcp_p": 0,
			"cv_p": 0,
			"cvp_p": 0
		}
	}
}

That is pretty unfortunate as I'd rather have openwrt running on the front line than the 7490 with a more one year old OS which in addition makes it difficult to route VPN traffic over the 7362SL to the lan https://forum.openwrt.org/t/openvpn-server-general-understanding-of-forwarding-and-routing/139387
But that's another story