Gap and loophole between content and buildings insurance?

For leasehold properties, I have recently been advised leaseholders may be exposed to some gap and loophole between home content insurance and building insurance (usually taken by the management company or freeholder).

Can anyone with more experience in the field advise how the best we can cover ourselves, please?

Case 1. Typically, home content insurance doesn’t cover any fixtures (e.g. internal wall paint and structure, floor, built-in cabinets etc), some building insurances cover and some don’t cover fixtures.
In event of a water leak, the leaseholder could be left with no coverage for the wall, floor, kitchen unite damages, if the building insurance won’t cover fixtures.

2. In a few recent leak damages (myself and others), where a small leak (constant dripping) can be often blamed for damp or condensation by “leak specialist” (which were proven wrong at the end). The building insurance won’t cover the damage from damp or condensation and leaseholders were left to pay for the full repair.

Can anyone with more experience in the field advise how the best we can cover ourselves, please?

Many thanks

Mike