Excuse me, but this sounds like the whole screen display is the issue (an intelibox problem) or do you mean the individual icons that represent the contact points are blinking ?

If the latter you will need to explain what type of ground/return wiring you are using.

Other than that I would check that that the Power10 and the intellibox feeds to the track are in phase and isolated ( except , maybe, the Brown if you rely on a common ground. )

Is the Brown from the intellibox itself connected to anything ? if so what
Is the ground (upside down "T") from the (at least one) s88 connected anywhere
Please confirm you are using Marklin (style) s88s , or are they loconet variants

For most new boosters and control units there is no inherent connection of circuits.
If you have a one end of a sensor connected to the track that is fed from the Power10 and the other end of the sensor is connected to the s88 these have no relative context unless there is a circuit return.

The most common way to achieve this is to tie the outputs of the Controller and Booster grounds together.
WARNING. Do not tie the inputs from transformers/power-supplies together.

That said, my preference is NOT to use the track ground for the sensor return and use a totally isolated return wire for all sensors.
Unfortunately the concept of the 3-rail contact track (wagon wheels short the 2 rails together) upsets this ideal so if you are using these you will need to focus on the common return to ensure a clean circuit.
The 3rd option is to use an isolated current detection circuit (Like the Uhlenbrock 63320 for loconet)