Torture test for a TT rig!

Try the Shure Audio Obstacle Course.  
On headphones.

The Shilabe is a very low compliance cartridge.  The Triplanar is considered a "medium" mass tonearm, at 11g.  Yes, your problem certainly could be due to a mismatch of very low compliance with a tonearm of inadequate effective mass.  A cheap and dirty way to confirm that would be simply to add some weight at the headshell of the TP.  A US nickel weighs 5g, I think. (But don't take my word for that; weigh it.)  If adding 5g or even 10g on or near the headshell ameliorates the problem, you have your answer.

The amplitude of 1812 (cannon shots) does not exist in real music, so why do you use it as a test for a low compliance cartridge? Do you expect it to track like 30cu MM?

You can use Hi-Fi News Test LP, but even those last 2 bands are extreme test for cartridge suspension.

Play real music, you can damage your low compliance cartridge testing it on 1812s cannon shots, probably you already damaged it.

Few setups can flawlessly trac the Telarc 1812, so don’t read too much into your cartridge skipping over the cannon shots. If you want a good gauge of your turntable performance I’d recommend something like the HiFi News test record.