I had a similar issue on the 2830 - managed to fix the HTTPS issues by disabling the LINE IM protocol check in the default CSM firewall rules. Using the Syslog data it wasn't too hard to narrow it down to this rule, but it shouldn't have been required.

5 weeks with Draytek support, for them to come back with "don't enable the LINE option", was a waste of time. Asked for assurances as to whether this is the only thing affected, as I'm about to put forward a proposal to my boss to replace our 2830s with 2960s, so far stony silence.

I would just reiterate the need to report these issues to Draytek support directly, they've sat on my ticket for god knows how long and just come back to tell me that they can't recreate the problem and asked "does it make a difference if I change the HTTPS management port?". I'm loathe to flash the firmware for what will be the 5th time to change the management port which will then stop my SSL vpn working as well as all the other problems this firmware causes :x

Well you've got further than I have. I've been contacted by Draytek support only to confirm a typo in my support request (serial number = model 2862 - request = model 2762). I suspect that the 3.8.9.1 firmware is so broken that its a mammoth task to fix. I also pointed Draytek support to this post, so if anyone is experiencing strange unresolvable issues with the 3.8.9.1 firmware that can only be resolved by reverting to an older version - Tell us about it here It appears so far that only ~10 of us are experiencing issues.
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I was under the impression that this was THE top of the line SOHO router. Certainly doesn't feel like it. I'm considering installing pfSense in a VM and using the Draytek 2862 as a glorified modem.

Yes
running 2762ac (upgraded from 2760 - my fault for being an early adopter
had to downgrade t previous version

maybe should send it back to dealer
disappointed

Resisted temptation to use as modem. I could feel it in my waters that a new revision was just around the corner.. Been using 3.8.9.2_BT for the past couple of days. Can confirm issues I had experienced are fixed. Yay

I like to live life on the edge. Tested for 20 odd hours concluded it was working and went on holidays. Just tested some remote services still working.

TighterThan wrote: Resisted temptation to use as modem. I could feel it in my waters that a new revision was just around the corner.. Been using 3.8.9.2_BT for the past couple of days. Can confirm issues I had experienced are fixed. Yay

I like to live life on the edge. Tested for 20 odd hours concluded it was working and went on holidays. Just tested some remote services still working.

I've given up, both with the firmware and with their support. Tried 3.8.9.2 and the problems were getting weirder and weirder. I host a website and one of my website users simply couldn't access the website, I tried it on multiple 4g connections and another broadband connection and it worked fine, he tethered his phone to his laptop and it worked fine, just as I was about to tell him to report it to Virgin Media I thought about downgrading the firmware to 3.8.8.2 again and what do you know it started working properly again. Also I noticed that 3.8.9.2 was allowing pings between my different LANs which should've been blocked by my firewall rules and as soon as I downgraded it started respecting my firewall rules again. My Fingbox appliance had confirmed connections to the Fing servers on the right ports but they couldn't detect it, again as soon as I downgraded it starts working again even though the outbound connections are showing up the same on both firmware versions. There's definitely still problems and I've lost faith with Draytek support to fix them