"due to various" is a correct and usable phrase in written English.
You can use it to refer to a variety of reasons. For example, "Due to various complications, the surgery will need to be rescheduled."
Due to various technical reasons, the singers Chris and Gemma sounded dreadful on the night.
Then the message everyone fears crackles over the speakers: "Due to various incidents, traffic on the whole line is delayed.
In the buildup to the Olympics in Barcelona in 1992, he had to undergo eight operations due to various ailments.
These costs are due to various factors.
signals due to various radical species.
This deviation comes due to various losses under field conditions.
This which may be due to various factors.
Fig. 2 Topographic images due to various tip separations.
This has been done due to various reasons.
At the center is the key solution provider, whose size is variable due to various factors.
However … EarthLink is not a particularly useful comparable due to various differences between the two companies".
