Aluminum windows outside and inside - so fully aluminum

"In the past, aluminum window frames were made from a single piece. Since aluminum is a more heat-conductive material, earlier aluminum windows formed a thermal bridge, which caused corresponding heat losses.
Therefore, today aluminum window frames are usually made from an outer and an inner shell to improve the thermal insulation of the frame (cf. Uf-value of window frames). Such thermally separated aluminum window profiles provide insulating properties that can be compared to those of wood or plastic.
The insulating effect results from the special two-shell construction of the aluminum window profiles, which are also equipped with multiple chambers, into which air or even better: insulating material is filled.
Care is also taken to ensure that the profiles are designed so that thermal barriers (so-called insulation cores) exist between the outer shell and the room-side shell, so that no unwanted thermal bridges occur through which heat is uncontrollably lost. Aluminum profiles designed in this way achieve good to very good insulating properties."

And: did you not get advice about the advantages and disadvantages before making such an expensive decision (aluminum windows)?

Nevertheless, aluminum windows "feel" colder because heat is drawn away from the body faster (transferred to the window).
This "feeling" does not require direct contact with the surface. Perhaps a general increase in room temperature and thus an increase in the temperature of the window components would help? Have you ever measured the surface temperature? What is it?

And yes, compressed tape is actually better (in my opinion), of course it always depends on the installer whether it turns out well.

[*]House built in 2018
[*]Aluminum windows with triple glazing
[*]Underfloor heating
[*]Wall construction
[*]No problem in summer

[*]Window color anthracite gray.
[*]External sun protection available
[*]Windows installed in the outer third of the wall in the insulation layer in front of the "wall."
[*]Deep window reveals on the room side without "extra" heating loops/heating circuit in front of the windows.
[*]Modern aluminum windows with today’s average Uf values.

[*]Dark aluminum window frames can become extremely hot on the outside in summer without sun protection, especially on the east and west sides of the building. > 80°C is possible.
[*]Aluminum window frames with sun protection in front of glass and frame also become warm in the sun depending on the outside temperature, exceeding 40°C.
[*]If the large summer temperature differences do not transfer to the inner thermally separated shell of the windows, the installation and the window are faultless = no extraordinary thermal bridges are present.
[*]In winter/... highly insulated buildings with low-temperature underfloor heating and deep window reveals, a poorer Uf value of the window frame compared to the triple glazing and wall insulation has a corresponding effect on the frame. Especially with underfloor heating.