problem with following the metronome.

I have big problem with following metronome when either triplets or dotted notes are present.

Do you have any advice?

Accent the first note of the triplet in your head ON the beat. ONE - Trip - Let, TWO-Trip-Let. That helped me when learning them on drums. They soon became a favourite and transfered easily to the guitar. DA da da DA da da DA da da. TA da da TA da da. It'll work.
A dotted note is another beast entirely simply adding half the value of the note to itself. A dotted half note for instance is worth 3 beats in 4/4 time but still counted (onetwothree)-4. IN the same 4/4 time signature a dotted quarter would be worth 1.5 beats like a quarter note and an eighth note tied together.

Start slow - the speed will come with practice.

Start slow - the speed will come with practice.

+ 1000

Here's a way to count with dotted quarters, count the measure in eighth notes and use a one on each new note start; for example, if you have a 4/4 measure with the common swing rhythm of a dotted quarter followed by an eighth note, count ONE two three, ONE two three four five. If you have two dotted quarter notes followed by a regular quarter note in a 4/4 measure you would count ONE two three, ONE two three, ONE two. Keep the count steady and clap/play each time you say one, this works well for more complex funk style sixteenth based rhythms too, but try it with dotted quarters to see if it works for you.

I count 1-and-uh, 2-and-uh... But slow and steady wins the race!

My post was for dotted note counting, the "1 and Uh" counting is for triplets or swing rhythms, the OP asked about both. Complex rhythms like one finds in funk or bossa nova music, for example, are based on straight eighth or sixteenth note rhythms mostly.

Combinatorial counting, where each new event gets the number one, is a great way to get the right accents in these types of music. ONE two three, ONE two three, ONE two, ONE two, ONE two, or stomp clap clap , stomp clap clap, stomp clap, stomp clap, stomp clap (as the actors/dancers do it), is an easy way to learn a well known complex notated rhythm in alternating 6/8 and 3/4 time signatures (in this case Bernstein's "America" from "West Side Story"). Clave rhythms like the Bo Diddly Lick rhythm become: ONE two three, ONE two three, ONE two three four, ONE two, ONE two three four. I find it cuts the learning time to a fraction when ingraining tough rhythms as opposed to counting them with the traditional one-e-and-a methods, YMMV:cool: