Just as an idea of getting more information out of your modem, here is what I put into /etc/rc.local:
# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.
# default is 4, 1 and 2 are a firehose, 3 spits out something at retrains
echo "LOG 3" > /proc/driver/mei_cpe/config
echo "TRACE 3" > /proc/driver/mei_cpe/config
# get the DSL stats
#ubus call dsl metrics
# manual calls:
#dsl_cpe_pipe.sh help
#dsl_cpe_pipe.sh g997listrg 0
exit 0
Which made the DSL startup print a few things into the dmesg...
What version have not worked for you before you tried snapshot? Have you used/tried this release? https://downloads.openwrt.org/releases/22.03.0-rc4/targets/lantiq/xrx200/openwrt-22.03.0-rc4-lantiq-xrx200-avm_fritz7362sl-squashfs-sysupgrade.bin
This should be the most simple version to start from at the current release state.
I have tried many versions ... I will try your link and tell you if it works ...
This dont work for me, the BootLoader:
https://downloads.openwrt.org/releases/21.02.3/targets/lantiq/xrx200/openwrt-21.02.3-lantiq-xrx200-avm_fritz7362sl-initramfs-kernel.bin
After installing I cant connect to ssh. A nmap says hot ist down.
Strange, because exactly same version worked fine for this person: No dsl connection with Fritz!Box 7362 SL - #7 by RSX7
After the installation of this version you have luci preinstalled at least. And dont forget to delete the settings when installing it or reset the settings after installation.
And because you are also on a ADSL line like the other person, this could matter for you: No dsl connection with Fritz!Box 7362 SL - #8 by godraselti
here the errors:
root@(none):~# cd /tmp/
root@(none):/tmp# sysupgrade openwrt-22.03.0-rc4-lantiq-xrx200-avm_fritz7362sl-squashfs-sysupgrade.bin
Device avm,fritz7362sl not supported by this image
Supported devices: avm,fritz7362sl - Image version mismatch: image 1.1, device 1.0. Please wipe config during upgrade (force required) or reinstall. Reason: Config cannot be migrated from swconfig to DSA
Image check failed.
root@(none):/tmp#
@godraselti
Is the DSL now working for him?
https://forum.openwrt.org/t/no-dsl-connection-with-fritz-box-7362-sl/130683/6
I have downloaded the firmware files and will try it...
sysupgrade -F -n openwrt-22.03.0-rc4-lantiq-xrx200-avm_fritz7362sl-squashfs-sysupgrade.bin
Or just -F and later in luci reset the config.
okay, i was doing the steps ... sysupgrade works fine with your trick. I have copied the DSL firmware to /lib/firmware and set the right path to it ... But No DSL support.
I think, the modem chipset is not suupported by openwrt. thats sad 
root@OpenWrt:/lib/firmware# ls -l
-rw-r--r-- 1 root root 1088 Jun 10 07:20 ath9k-eeprom-pci-0000:01:00.0.bin
lrwxrwxrwx 1 root root 43 Jun 10 07:20 lantiq-vrx200-a-to-b.bspatch -> xcpe_581816_580B11_to_579906_574402.bspatch
lrwxrwxrwx 1 root root 22 Jun 10 07:20 lantiq-vrx200-a.bin -> xcpe_581816_580B11.bin
-rw-r--r-- 1 root root 4316 Jun 10 07:20 regulatory.db
-rw-r--r-- 1 root root 908888 Jun 10 07:27 vr9-B-dsl_s6QpaNxxn0BCugT.bin
-rw-r--r-- 1 root root 1920 Jun 10 07:20 xcpe_581816_580B11.LICENSE
-rw-r--r-- 1 root root 898952 Jun 10 07:20 xcpe_581816_580B11.bin
-rw-r--r-- 1 root root 253635 Jun 10 07:20 xcpe_581816_580B11_to_579906_574402.bspatch
Its better do delete it from the wiki page, isnt it? Cause the wiki says, its supported ...
Well, are we sure yet that the device does not work at all? What I see is two recent reports of having issues with 1&1 over ADSL, but the device might work just fine with VDSL2.
Here is a link to the most recent fb7362sl firmware blob (follow at own risk):
https://fastupload.io/w6dcTS7QarMvurm
ah, you have a fritzbox 7362SL, too? with VDSL?
I have started my box, over 200 times today 
and flash images ...
OK, i will try a last time ... by the way, thx for helping me ...
I think its better to buy a router, thats supported FULL openwrt, with WLAN/DSL/USB-storage and FULL iptables.
No, I do not. This is why I said "might work just fine with VDSL2" and nothing more definitive
The problem is there are only few router models that support DSL under OpenWrt and most of these are pretty old by now. Personally, I tried an FB7490 equivalent (BT HomeHub5A) as all-i-one router under OpenWrt and found it to be lacking even at 50/10 DSL speed. So I opted for operating the HH5A as bridged modem in front of a beefier router.
Not sure what your iptables issue is, but as far as I can tell iptables is spilt into a number of packages and depending on one's needs one needs to install the correct set of packages...
But I guess first goal needs to be getting on-line at all before wondering about additional packages.
Bro, it works !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Thank u very very much !!!
Post your working /etc/config/network, could be good for future reference.
Remove any password etc.